iiuiiimunjui.»imw i i .^ WILLIAM eMCRSOM Rf'^'f'^- i 1 ®ije §. P, ^tU pkarg ^ortI| Carolma ^tat£ (Kolkg^ QH506 Rfe ^Lu»^^j.n..«u-»n..-t..i|ni..„m,|i||,m|| v.d NORTH CAROLINA STATE UNIVERSITY LIBRARIES S02664258 X Date Due 1 1 ^y^m^j^m > A e^OecS Sit P ^Mar'5q ,i?)ul'59i V 4Aug'5< 1963 DEC 4 i»L ^ n >$£P ] / /C ><:^- AC/ / • BOOKS BY WILLIAM EMERSON RITTER The Higher Usefulness of Science. The Probable Infinity of Nature AND Life. The Unity of the Organism, or the Organismal Conception of Life. Illustrated. The Unity of the Organic Species, WITH Special Reference to the Human Species. War, Science and Civilization. An Organismal Conception of Consciousness. RICHARD G. badger, publisher, boston FIGURE 56. SKELETOX OF PYTIIOX. THE UNITY OF THE ORGANISM OR THE ORGANISMAL CONCEPTION OF LIFE BY WiTXiAM Emerson Ritter Director of the Scripps hislitiitlon fur liiologiiul Research of the Univirsity of Calif ornia. La Jolla California TWO VOLUMES VOLUME TWO ILLUSTRATED BOSTON RICHARD G. BADGER THE GORIIAM PRESS Copyright, 1919, by Richard G. Badger All Rights Reserved This work contains the text of the book: "An Organismal Theory of Consciousness." Made in the United States of America The Gorham Press, Boston, U. S. A. -z. o ^CL ^ %)NTENTS ^^%, !>. ->>. ?^RT I CRITIQUE OF THE ELEME^^TALIST CONCEPTION OF THl. ORGANISM B. The Production of Individiuils by Other Iiulir'nlual.s {<'i,iirlii(ltii) CHAPTER PACK XIV. Evidence from Metazoax Germ-Cells That Substances Other Than Chromatin Are the Physical Bases of Heredity .......... I Evidence from spermatozoa, 1. Spermatozoa sultjcrf to heredity as well as "bearers of heredity," 1: (a) ////<.*- trated by the ontogeny of mamm^ilian sperm, 4; {b) Illus- trated by the ontogeny of an insect sperm, 9. Evidence frt^m the ovum, 15: (a) eggs of ascidians — the facts, HI; (b) Conklin's interpretation, 19. Critical examinatix)n of Conk- lin's interpretation, 23. XV. Evidence from Somatic Histogenesis in the Mui.ticei.i ri.vR Organisms 32 The mitochondrial theory of heredity, 32. The mitochon- drial theory tested by the ontogeny of spermatozoa, .ill. The mitochondrial theory tested by histogenesis. ,/,\ The un- tenable hypothesis that cytoplasm of the ovum /.v inheritance material for general but not for special characters, /fO. Spe- cies attributes in single cells of adult (nganisnis. //.I. The spiwules of the ascidian genus slyela, Jf.'f. The spicuhs of sponges and other invertebrates, oO. The "hair.s" of hight r phmts, 55. Cell~7vall structures in hightr plants, 57. The morphology of striated muscU ptx'rs, 60. Tlw physiology of muscle fibers, 61. Summary of positive information tUxuif the physical bajtis of heredity, 6'f. XVI. The Inheritance Materials of Gehm-Cei.i.s Initiators Rather Than Determiners ...... Ctd Antecedents of the cytoplasmic and nuclear thiories of i»»- ix i;j o'-^ xu . Contents CHAPTER PAGE reasoning, S06. Theories of animal behavior in relation to the "science" of zoology, 208. XXII. Psychical Integration 214« Preliminary remarks: (a) Absolute discrimination between re/lex and psychical phenomena not necessary, 214; {b) The organism an original datum in all problems of psychic life, 215; (c) Provisional classification of psychical facts, 217. Likeness between tropistic and higher psychic activity, 220. First move toward shoiving the organi^mal character of the higher psychic life, 227. Associationist psychology a special case of elementalist biology, 228. Preliminary examination of objective and subjective, 231. The essence of Wundtian apperception, 232. Remarks on analysis and synthesis, 236. XXIII. Organic Connection Between Physical and Psychical 239 A still closer look at the organismal nature of tropisms, 239. The automatic and anticipatory character of tropisms and other reflexes, 241- A still closer look at the likeness between higher rational life and tropisms, 242. A still closer description of the subrational moiety of psychic life, 246. Remarks on the classes of subrational life, 246. Four certainties about the adaptiveness of subrational psychic activities, 250. Generally useful to individual and to species, 250. Many useful to species primarily, 250. VafiabiUty of subrational activities, 251. Tendency of subrational activ- ities to excessiveness, 256. Summary of organisnud charac- ter of all subrational 2}sychie life, 274- Specificity of subra- tional psychic life, 276. XXIV. Sketch of an Organismal Theory of Consciousness . 283 Remarks on the hypothetical character of this chapter, 282. The natural history method and the study of one's self, 282. Formulation of the central hypothesis, 286. Preliminary justification of the hypothesis as such, 287. More systematic justification of the hypothesis, 291. The nature of "outer" or objective and "innef or subjective, 292. As to the lowest terms of self -consciousness, 308. Instinct and physical or- ganization, 310. Emotion and physical organization, 316. Glance at the equilibrative interaction between "body" and "soul," 323. Support of the hypothesis by the physico-chem- Contents xiii CHAPTER PAGE ical conception of the organism, 32/f. Personality and ele- mentary chemical sut)stances, 327. On the psychology of subjective and objective personality, 331. Personality and the "breath of life" viewed in the light of physical chemistry of the organism, 336. Postscript . . . . . . . . . . . .351 BiBIJOGRAPlIY ........... 359 Glossary ............ 377 +^DEX »»»«». .tt'*.. oJ I 4 LIST or ILLUSTRATIONS FIGURE PAGE 56. Skeleton of Python Frontispiece 36. Sperm of Fur Seal (After Oliver) 37. "Young" Spermatid (After Ballowitz) 38. S])ermati(l of Fur Seal (After Oliver) 39. Spermatid of Fur Seal (After Oliver) 40. Spermatid of Fur Seal (After Oliver) 41. Spermatid of Fur Seal (After Oliver) 43. Development of Sperm of Argas Miniatus (After Casteel) 10, 11 43. Development of an Ascidian Egg (After Conklin) ... 17 44. Spinule Cell of Styela Yakutatensis (After Huntsman) . 44 45. Spinule Cell of Styela Plicata (After Huntsman) ... 45 46. Spinule Cell of Styela Greeleyi (After Huntsman) . . 46 47. Spinule Cell of Styela Montereyensis (After Rittcr and For- syth) . 47 48. Spicules of Sponges (After I.ankester) 51 49. 50, 51. Development of a Spicule (After Lankcster) . 52, 53 52. Trichomes of Papaver Orientalc (After Cannon) . . . 55 53. Trichomes of P. Pilosum (After Cannon) .... 55 54. Trichomes of P. Somniferum (After Cannon) .... 55 55. Side View of Amphioxus (After Parker & Haswell) . . 95 57. Tentacle of Halocynthia Johnsoni (Schematic; After Kilter) 98 58. Acacia Elata 99 59. Vicia Gigantea KM) 60. Cassia Sp KM) 61. Sequoia Sempervirens K)l XV PART I CRITIQUE OF THE ELEMENTALIST CONCEPTION OF THE ORGANISM B. The Production of Individuals by Other Individuals %. \ .^5 THE UNITY OF THE G^^NISM Chapter XIV ^^^ EVIDENCE FROM METAZOAX GERM-CELLS THAT SUBSTANCES OTHER THAN CHROMATIN ARE THE PHYSICAL BASES OF HEREDITY Evidence from Spermatozoa T N our discussion we will be guided by the principle laid -*■ down earlier and followed throughout our treatment of heredity in the Protozoa, namely, that descriptive onto- genesis brought to bear on the actual transformations which result in the production of specific organs and parts, is the final tribunal for the determination of what substances are hereditarily formative. The first inquiry will Ik? whether there exist among the metazoa single-cell organs or parts which when fully formed exhibit species characters in the sense of taxonomic biology. If such elements do exist, ob- servation on the constituents of the undifTerentiated cells which take part in the transfonnations, obviously may be expected to give us the information sought as to what substances are formative. Spermatozoa Subject to Heredity as Well as "'Bearers of Heredity** The comparative anatomy and comparative ontogenesis of the male germ-cells among animals, which have been pur- sued with great assiduity and skill during recent decades, 1 2 The Unity of the Organism furnish perhaps the largest mass of relevant facts we pos- sess from any one field. Innumerable researches on fully formed spennatozoa, the greatest single research being that of Retzius, give us ex- tensive knowledge of the variety of structure of the sperma- tozoa in the larger and smaller taxonomic subdivisions of the animal world. It would be going beyond the evidence to say that every well-characterized animal species may be identified by its speraiatozoa ; but unquestionably the trend of investigation has been toward such a conclusion. I believe, for example, it would be impossible to assert on the basis of evidence that any two species of animals belonging to different genera, no matter how much alike if their dis- tinctiveness is not questioned, have indistinguishable sper- matozoa. "One may say," writes Ballowitz, "that each ani- mal species has its own sperm-form of definite size." ^ An attempt to illustrate fully this variety of form and size by specific examples is out of the question here. We will refer only to the specificity of the sperm of man himself. Ret- zius was able to compare in detail sperms of the Chimpanzee, Orang-Utan, Gibbon, and Homo, and found that while their resemblance is rather close, each possesses clear differential marks. For example, the spiral structure of the envelop of the central piece is considerably more distinct in the Chim- panzee than in Homo. Worthy of mention is the fact that, according to Retzius, the sperm of the Chimpanzee resembles that of Homo more closely than does that of the Orang, thus falling in with the fact that in several particulars of adult structure the resemblance of the Chimpanzee to man is closer than that of the Orang. The spermatozoa of a given animal group having a closer resemblance to one another than to those of other groups; in other words, having a resemblance due to descent, are themselves subject to heredity and are not alone concerned in the transmission of hereditary attributes from parent to Evidence from Metazoan Germ-Cells 3 offspring. Especially lm])()rtant for us Is it to notice that to a great extent the diversity of structure among s])erniatozoa is in the locomotor organ, the tail; that is, the organ cliieflv concerned with the unique life of the sj)erm as such, and very little if at all concerned directly with fertilization and hence with hereditary marks of offspring. This fact de- serves attentive consideration. "In its more usual form tlie animal spermatozoon resembles a minute, elongated tad- pole, which swims very activel}^ about by the vibration of a long, slender tail." - In some respects comparison of the spermatozoon of the type here indicated with an Ap])en- dicularian, a minute Tunicate which possesses a tail through- out its life, is more instructive. Any one who has had op- portunity to observe both sperm cell and appendicularian when alive and active will not have failed to remark the general resemblance, not only as to form but as to kind of movement in the two cases. Is the develoj^ment of tlie Appendicularian's tail a manifestation of heredity.'' Surely no one would think of giving any but an affirmative answer. How, then, deny that the development of the spermatozoon's tail is also a manifestation of heredity.^ I cannot see that it would be less inconsistent to affirm that the wriggling ap- pendicularian is alive but that the wriggling spermatozoon is not, than to affirm that the ontogeny of the first is guideil by heredity while that of the second is not. TO" bring the point onto somewhat more familiar ground, let us revert to Wilson's comparison of the spermatozoon to the tadpole stage in the life of the frog. Our contention is that the tail of the frog's spermatozoon is as indisputably modeled by heredity as is the tail of the frog's tadpole, and consequently that we are bound to search for the physical basis of hered- ity in the former as well as in the latter. Our inquiry is, then. What observations have we as to the substances con- cerned in producing the spermatozoon tail.? 4 The Unity of the Organism (a) Illustrated hy the Ontogeny of Mammalian Sperm Without exception, so far as I know, positive description of spermatogenesis affirms that the tail is produced from h-c, vi-:SS»i>;:i ■CI TX, ra.p. FIGURE 36. SPERM OF FUR SEAL ( AFTER OTJ^^ER). h.c, head cap. n'k., neck, c.p., connecting piece, c.r., cytoplasmic remnant, g.a., anterior granules. g-P-> posterior granules, an., annulus. m.p., main piece, e.p., end piece. other parts of the spermatid than the nucleus. For the lit- tle we can do in the way of giving objectivity to this general statement we will first examine the nearly mature, typical Evidence from Metazoan Germ-Cells 5 mammalian spermatozoon (fi^aire 36) of the Fur Seal. For the origin of the various parts we will make use of the summary given by Ballowitz (figure 37). Concerning FIGURE 37. "yOUXG" SPERMATID ( AFTER BALLOWITZ). 1, nucleus. 2, centrioles. 3, idiosonie. 4, mitochondrial body chromatoid body. 6, spindle remnant. 5, the nucleus, i, "it is certain that in all animals the chroma- tin-containing part of the sperm proceeds from thu nucleus." ^ On this point there is agreement among observ- ers ; so whatever may be the truth about the sperm-chromatin -rt FIGURE 38. SPERMATID OF FUR SEAL ( AFTER OLIVER ). n., nucleus, c, centrioles. a.f., axial filament. as the physical basis of heredity for tlie adult animal, there is no question about its being such for the liead of tlie spermatozoon itself. 6 The Unity of the Organism The centrioles {2, figure 37) are "almost always double and occupy a place in the spermatid close beneath the surface of the cell." ^ The pair is typically so placed that the axis joining them is perpendicular to the surface of the spermatid^ the member s- FIGURE 39. SPERMATID OF FUR SEAL ( AFTER OI.IVEr). h.c, head cap. n., nucleus, p.c, proximate centriole. centriole. a.f., axial filament, s., remnant of sjihere. d.c, distal toward the surface being known as the distal centriole and the one toward the center of the spermatid the proximal centriole (figure 39 d.c. and p.c). As to the part played by each of these in the development of FIGURE 40. SPEBMATID OF FUR SEAL (aFTER OLIVER). n., nucleus, c.h., chromatin granules, c.t.f., caudal tube filaments. the sperm we learn that after migrating inward until they come to lie very near the nucleus, if not in actual contact with it, the centrioles begin their development with the following out- come: "The proximal centriole . . . divides into two portions, closely adherent to the nuclear wall, each connected by a fila- ment to one distal group. The distal centriole divides into an Evidence from Metazoan Gcrm-Cclh 7 anterior and a posterior }3ortion. The posterior portion becomes the anniilus {an., figure .S(j) while tlie anterior one divides again, forming the Xoduli i)osteriores" * (g-P-, figure 'Ui). Throughout their career these bodies or granules are highly stainable with certain dye-stuffs. Out of the idiosome (S, figure ti7) which as a rule is a body "fiir sich" — in itself alone — develops the ])erforat()riuni. or lnad cap of the adult sperm {li.c, figure 3()). It is agreed that the mitochondria {Jf, figure 37) in the spermatids of many animals, particularly of many vertebrates "furnish the material" ^ for the spiral found in the connecting piece {c.p., figure 36) of the sperm. Although no spiral is present in the Seal sperm it may be represented, according to Oliver, by numerous graTiulcs sur- rounding the axial filament in the connecting piece, l^ut while the connecting piece of the Seal sperm seems not to be tyi)ical as regards the spiral, it presents another structure, the caudal tube, or "manchette" of some authors, in a form which is s])ecially instructive from our standpoint. In the adult sperm this struc- ture is a thin sheath enveloping the cytoplasmic ])art of the con- necting piece and lying in close contact with the persisting cell membrane. The point of special interest about it is that its persistence in the completed sperm of the Seal a))pears to be exceptional, for it is known to disappear entirely in the course of development of the sperm of several other mammals. It is a transitory or embryonic organ in some species of sperm, but a permanent one in other species, just as gills, for exam|)le. are transitory organs in the ontogeny of some species, as a frog, but are permanent in others, as fish. The development of the tube in the Seal sperm is es])rcially favorable for observation. "It may be reajclily followed." writes Oliver, "from its first appearance up to its final incorporation in the connecting piece as a peripheral layer, or sheath." ^ Here then is a structure having all the essential marks of devel- opment due to heredity and likewise one the "physical basis" of which has been carefully observed. Mentioning a long list of investigators who believe in the "derivation of the caudal tube by a process of cytoplasmic differentiation alone" Miss Oliver fells us that her study of the develo])ment of the fur seal sperm is a complete confirmation of this view. As to the very begin- ning of the tube we read: "Shortly after the centrosomes and their tail filament have reached the nuclear membrane there appears in the cj^toplasm surrounding the axial thread a series 8 The Unity of the Organism of delicate filaments attached to the nuclear membrane. The proximal ends of these arise in a circle around the basal end of the nucleus with the centrosomes as a center^ while their distal ends project freely into the cytoplasm." ® (figure 40 c.t.f.) These filaments "are at first very short and thin^ but they in- crease in length and thickness rapidly. By the progressive dif- ferentiation of the cytoplasm between them they soon fuse into a hyaline tube, surrounding the axial thread and open at its lower extremity." (figure 41, c.t.) The capital point is that we have here a well-defined structure the development of which is in- an FIGURE 41. SPERMATID OF FUR SEAL ( AFTER OLIVER). h.c, head cap. c.t., caudal tube, an., annulus. dubitably proved to depend primarily on parts of the cell other than the chromatin. Indeed no one, apparently, has pretended that the chromatin takes a part in its production, for even those investigators who have not believed that it arises from the cyto- plasm alone have held that it originates from the membrane of the nucleus. About the chromatoid body (5) and the "spindle remnant" (6) (figure 37) J, little need be said in this connection as they seem to be inconstant structures the significance of which is in much doubt. Finally, mention should be made of the fact that a con- siderable portion of the cytoplasm is cast off entirely in the ontogeny of the sperm of many animals, as for example the seal, Exndence from Metazoan Germ-Cells 9 the body (c. v., figure 36) being all that is left of tlie substance at the late stage represented. So uuieh by way of ilhistratiou of the portions of the s])ermatid, or germ of the sjKrniato/oon. in the vertebrated animals, for des])ite the great variety in struct- ural details presented by the s))('rm of this part of the animal kingdom I think all will agree that so far as concerns the chief ))oint being made in this discussion, what we have ))r('sont<'d is true of the whole ])hylum. (b) Illustrated by the Ontogeny of an Insect Sperm We will now examine the ontogeny of a very different type of speiTn, from another portion of the animal kingdom, the insecta. The particular species chosen is the fowl-tick {Argas miniatus). The investigation made use of is by Doctor D. B. Casteel. The series of figures (42 a, h, c, d, e, f, g,) will help to an understanding of the remarkable, almost unique sperm and spermogenesis in this animal. Figure 42rt shows the nearly ma- ture primary spermatocyte. Especially to be noted are the mitochondria, mi., scattered uniformly through the cytoplasm, and the striated layer, *. /., on the outer surface of the cell. This layer is sharply demarked from the underlying cyto})lasui. The striae, disposed perpendicular to the surface of the cell, are excessively fine, and when looked at in situ end on "suggest the appearance of a faceted compound eye or of honey-comb." ® Concerning the genesis of this layer Casteel says, in a personal letter, that the layer begins to appear at the surface and grad- ually increases in depth until the completed state shown in figure 42a is reached. "The striae," he says, "appear to be forming from the undifferentiated cytoplasm sheath." All the figures from 42 b to g have to do with the transforma- tion of the spermatid (figure 42b) into tiie spermatozoon, h'rom figure 42b one sees that the striated layer has disap})eared on one side of the cell and thinned out greatly in a smaller area on the opposite side; that the nucleus, n, has moved to the surface of the cell in the middle of the arr-a of disajipearance of the striated layer; that the large plasmosomes, pi. 42a have almost entirely disappeared from the nucleus; that the vesicular bodies r.h., as- sembled for the most part in the vicinity of the nucleus, are mi. r.'^j-M n. -S.I.. A m.r.'- rn.r. FIGURE 42. FIGURE 42. DEVEI.OPMEXT OF SPERM OF ARGAS MIXIATUS ( AFTER CASTEEl). a., rupture point of outer tube, c.p., cilia-like processes, fl., flagel- luin. f.p., finger-form jjrocess. g.e., gelatinous envelop, i.e., in- 10 nx>, FIGURE 42. vagination cavity, i.t., inner tube, mi., niitochondria. ni.r., mito- chondrial ring-, n., nucleus, o.d., oil droj^ict. o.t., outer tul»c. ]>!., plasmosome, s.l., striated layer, v.b., vesicular bodies. 1).])., l)egin- ning of inner tube. 11 12 The Unity of the Organism in processes of degeneration and disappearance; and that the mitochondria, mi, look as though they had collected into two well-defined spherical masses m.r., on the side of the cell oppo- site the nucleus and near the small area of thinned-out striated layer. As a matter of fact these two apparent mitochondrial masses are the opposite sides of a ring seen in optical section. Transformation of the general form of the spermatid now be- gins by the indentation of the side opposite the nucleus, this going on to produce first the quarter-moon shape shown at i.e., figure 12c. By the still further growth and narrowing the edges of the cup finally come together to produce the elongated cavity shown in figure 42d, o.t. This is the beginning of the outer tube which becomes long and relatively narrow as development con- tinues, (figure 42e_, o.t.^. At an early period in the growth of this tube the striated layer which naturally becomes shut into the tube breaks up over most of the circumference of the tube into what resembles a dense layer of long cilia. However, since the processes are not motile and later dissolve and produce a gela- tinous mass within the tube, their resemblance to cilia is only superficial. This account of the fate of the striated layer applies, as previously intimated, to most of the circumference of the outer tube. But the small thin area of the layer opposite the nucleus, shown in figures 42d and 42c, retains the cilia-like processes. This persistent basal patcli (b.p., figure 42d) is the starting point for an important part of the future spermatozoon, the "inner tube" so called by Doctor Casteel (i.t., figure 42e). While these profound changes are going on in the portion of the spermatid opposite the nucleus, a stout, somewhat finger- like process, (f.p., figure 42d) is formed on the nuclear side of the spermatid, into the base of which the nucleus migrates. In the meantime the vesicular bodies have entirely disappeared, and the mitochondria, no longer disposed in the ring of earlier stages, have assembled into an irregular, rather diffuse mass toward the basal patch {mi., figure 42d). At the time when the outer tube has reached its maximum length and is somewhat coiled, the inner tube, starting at the basal patch previously described, begins to grow into the cavity of the outer tube. This growth continues until the inner tube is approximately as long as the outer tube. Figure 42e presents an advanced but not completed stage of growth of the inner tube i.t. In reality, according to Doctor Casteel's interpretation, the inner tube grows at the expense of the outer tube, for when the Evidence from Metazoan Germ-Cells 13 two are of nearly equal length the entire spermatozoon is only about half as long as it was before the inner tube developed. All of the mitochondria of the cell are drawn into tlie inner tube as it grows, and finally form a deeply staining mass at the distal end of the tube {mi., figures 42e and ^ag). During these transformatory operations tlic nucleus, greatly reduced in size proportionally to the sjiermatozoon as a whole, has left its former place at the base of the finger-like j)r()eess, and been making its way along the wall of the outer tube, bur- rowing through the gelatinous layer on the outer })art of this tube {n, figure 4<2e). This migration continues until, when the distal end of the inner tube reaches nearly the end of the outer tube, the nucleus lies in the wall of the outer tube opposite the end of the inner tube {n, figure Igf.) The final act of transformation takes place after the sperm has left the male tick and lies in a spermatophore sac within the genital ducts of the female. This act begins with the per- foration of the end {a. figure 42f) of the outer tube by the inner tube. Through the opening thus made the whole inner tube finally passes, really by a slipping back of the outer tube, so that, the eversion of this latter being completed, the two tubes constitute one continuous tube. By this act of turning inside out, the finger-like process in which the nucleus formerly lay (figure 42d, f.p.) is brought into close proximity again with the nucleus. Some of the details of the final steps in the transformation Doctor Casteel has not yet been able to make out ; but these are of little consequence for our discussion. Nor has the act of fertilization been observed. Going on the usual cri- teria, the end of the sperm containing the nucleus would be regarded as the head. But surprisingly enough, in moving, the opposite end, the end containing the mitochondria, goes foremost. This sperm and its development are so unicpie as con- trasted with those occurring in most animal groups, that one might be almost inclined to question whether there may not be something wrong here — whether the case may not be one of diseased growth, or the result of manipulative mal- 14 The Unity of the Organism formation, or something else. Any such suspicion is, how- ever, completely done away with by the fact that much the same type of spermogenesis is known to occur in other ticks. Casteel cites particularly the observations of Katharine Samson on the development of the sperm of Ixodes ricinus and Ornithodes mouhata as furnishing cases to which that of Argas is "in many respects parallel." After all that has been said in the previous pages, it is almost needless to point out the significance for our general contention of this remarkable case of spermogenesis. Were we living in that comfortable era of life-philosophy wherein theologians studied nature for the purpose of proving that everything in it was made to meet some human need, we could easily recognize this case as one designed expressly to assist man in refuting the false dogma of Chromatinic Omnipotence in heredity. It is hard to imagine a developmental process in which denial of form-determining power to non-chromatinic, even non-nuclear parts of the cell would be a greater folly than would be the denial of cytoplasmic "form-determination" in the production of the striated layer of the spermatid, or of the growth of the outer tube, or of the inner tube, or of the turning inside-out of the outer tube. In fact, by far the greater part of the astonishing transformations here gone through are cytoplasmic, the nuclear changes being relatively slight. It may be worth while to remind the reader again, so boldly does the real truth about hereditary substance stand out in this case, that the cardinal evil in the chromatin dogma is that it implies the denial of great masses of the most direct observational evidence we have as to what the physical bases of heredity may be, and so tends to detract attention from them. We may predict that the important research which has made known this unique case of organic genesis will pass almost unnoticed by the geneticists of our Evidence from Metazoan Germ-Cells 15 day. Were their attention called to it they would probably frankly say that they have little interest in f^cnesis in tliis sense. That the sperm here described is not peculiar in every respect to the species Argas minmtus is certain from the meager comparative information we possess, as Casteel has shown. Nevertheless not merely general analogy, but strong indications contained in even the little comparative knowledge w^e have in this particular case, warrant the sup- position that in some respects the sperm of the species would be peculiar to the species, to say nothing of the genus, family and so forth. The development is, consequently, due to heredity, and the cytoplasm is "inheritance material" as ascertained by direct observation. Evidence from the Ovum We now turn to the ovum to see what can be learned con- cerning hereditary substance in the development of the ovum iself. Attention should be called at the outset to tlie important difference between the sperm and the ovum in the kind of specialization in each. The sperm, it will be noticed, is far more specialized for its own particular life than is the ovum, this "particular life" of the sperm con- sisting in its great power of locomotion. As a consequence of this difference, the ovum as an entity has no such sharp distinction from the ovum as a geiTninal element as has the spermatozoon. This difference is expressed in one way by the assertion that the fertilized ovum is the individual organism in the one-celled stage of its life. No such state- ment is ever heard about the spermatozoon for the obvious reason that the sperm does not transform directly into the embryo as does the egg. From the absence of so distinctive a character of the ovum as such, it happens that tlie hered- ity of the ovum is not so distinguishable from tlie heredity of the organism of whose life it is a stage, as is the case 16 The Unity of the Organism with the sperm. Nevertheless we are bound to recognize that the ^gg no less than the sperm has hereditary attri- butes of its own, and that other substances than chromatin play a demonstrable part in the production of these. In- deed the main discoveries concerning what in an earlier chapter was called the promorphology of the ^gg are of this sort. There is one kind of promorphology that is of special importance to the present stage of this discussion. I refer to the kind known sometimes as "germinal localization" and sometimes as "organ forming substances" in the ovum. The idea, expressed in a sentence, is that in the eggs of some animals, portions of the ^gg destined to give rise to par- ticular parts of the future embryo are visibly different from other portions before cell division begins, in some cases even before maturation and fertilization occur. According to our understanding of heredity, these distinguishable por- tions of such eggs are themselves hereditary attributes not only of the animal species to which the eggs belong, but of the eggs, no less than are distinctive morphological features of the adult animals or of any developmental stages. The study of these attributes of eggs is peculiarly interesting since, belonging to germ-cells par excellence, if we can get obseiTational evidence on both their origin and destination, we shall have direct evidence that one and the same substance is determined on the one hand by heredity, and on the other is a determiner in the strict genetic sense of hereditary at- tributes yet to be developed. («) Eggs of Ascidians — Tlie Facts Because of the great importance of the observations of E. G. Conklin in this field, and of his general views con- cerning the bearing of his observations on heredity, we shall make his work the center of our examination. One of the most important of Conklin's investigations was on the eggs Evidence from Metazoan Germ-Cells 17 of several species of Ascidians. Ainonfr the great merits of this investigation arc the facts that the normal living eggs were studied with great care, and that the comparative method was employed to a considerahle extent. ca. c rt. FiGURK 4:^. i)i:vp:r,op,^tKNT OF AX AsciDi.xN viAi (afikk coxki.ix). en., chorion, c.p., clear jirotoplasni. c.r.. crescent of niesodcrMial suh.stance. jLi'.N'., ^x'rniinal Ncsiclc. |).l>., polar- l)o- port the chromatin dogma of heredity.^ Readers wliose minds have become sensitized to the general type of reason- ing which pervades nearly all elementalistic theorizing and makes it to some extent fallacious, will readily anticipate about how the argument will run in this case. But it will be profitable to see it in actuality. After saying that ^'sonie of the important cytoplasmic substances can be actually seen to come from the nucleus" but that "this does not indi- cate that these substances exist from the beginning in the nucleus; on the contrary there is direct and visible evidence that they arise epigenetically," Conklin continues : **Such epigenesis, however, does not signify lack of primary organ- ization ; on the other hand all the evidence favors the vlrw 28 The Unity of the Organism that hack of the organization of the cytoplasm is the or- ganization of the chromosomes, which is definite, determinate and primary." ^^ (Itahcs mine). There you have it again ! Although it is freely granted that you can see the cytoplasm in the very act of arising epigenetically and moving about to become definitely located, that is, to become organized, still what you see is no part of the real essence of the business. "Back" of this, in the chromosomes, which, be it specially noticed, can not be seen to take any active part in the operations, we must conceive is the "organization" which is "definite, determinate and primary'' — in other words which is The Ultimate Cause, so far as heredity is concerned. Again I repeat, wearisome as the iteration has become, that the fallacy in this sort of reasoning is not in holding that there is some causal power "back" of the phenomena to be explained, but that all such power is located there. Tliat is, stating the general point in its application to the special case, the fallacy lies not in holding that the chromosomes contribute something to the hereditary attributes of the ascidians and other ani- mal groups whose development Conklin investigated, but in the implied denial that the cytoplasm contributes anything to it. Conklin probably would not admit that there is real contradiction between the observations by liimself and oth- ers, on the part played by cytoplasm in the early stages of development, and his contention that the evidence now "prac- tically amounts to a demonstration" of the correctness of the theory that the "chromosomes are the seat of the in- heritance material." What he would probably contend is that the observations are opposed merely to the extreme form of the chromosome theory. Thus, speaking from an angle of the general subject a little different from that of cytoplasmic localization, he writes : "This conclusion is not a refutation of the nuclear inheritance theory, but it is a Evidence from Metazoan Germ-Cells 29 profound modification of it." ^"^ And still more recently he has said, "Many biolo^^ists maintain that the nucleus and more particularly the chromosomes are tlie exclusive seat (jf the 'inheritance material' and that all the 'determiners' of adult characters are located in them. Against the extninc form of this theory many general and s])ecific objections may be urged. General objections are based upon the con- sideration that the entire cell, cytoplasm as well as nu- cleus, is concerned in differentiation and that neitiier is capable of embryonic development in the absence of the other. Differentiation is indeed the result of the interaction of nucleus and cytoplasm, and how then can it be said that the nucleus is the only seat of the inheritance material.''" ^* An elaborate discussion of whether the language here used can be harmonized with the statement (juoted above about the demonstration of the correctness of the chromosome theory, by saying that the views expressed in the last quota- tion merely involve a "profound modification of the nuclear inheritance theory" would smack too much of pure dialectics to deserve a place in this volume. Our sole concern is with the truth about the thing itself. Conklin's position would be so far satisfactory if he would permit/us to understand his statements "the entire cell, cytoplasm as well as nucleus, is concerned in differentia- tion," and the one about modification of the nuclear inheri- ance theory, to mean that cytoplasm is "inheritance mate- rial" and contains "determiners." Evidence that cytoplasm contains "determiners" is even more jjositive tlian is that for the theory that chromosomes are the seat of such things, for the simple reason that we can observe abundantly cyto- plasm. in the act of producing hereditary structures, wiiereas we rarely observe chromosomes operating directly in this way. But such permission would not, I fear, be forthcoming. If it would be, one is at a loss to understand why the terms "hereditary substance," "physical basis of heredity," "de- 30 The Unity of the Organism terminers," "factors" and the like, constantly used in con- nection with the chromosomes are never used in connection with cytoplasm. Indeed, so well does Conklin present the general argument for the participation of cytoplasm in the development of hereditary structures that it is surpris- ing, not to sa}'- disappointing, to find him neglect to present the most specific argument we have to the same effect, name- ly that the genesis of a vast range of such structures can be directly observed to be largely due to cytoplasmic trans- formations. One other passage in Conklin's general argument is so significant that we must reproduce it. "Differentiation is indeed the result of the interaction of nucleus and cyto- plasm, and how then can it be said that the nucleus is the only seat of the inheritance material.'^ If held rigidly, this theory involves the assumption that the cytoplasm and all other parts of the cell are the products of the chromosomes, and that therefore the chromosome and not the cell is the ultimate independent unit of structure and function ; an assumption which is contrary to fact. Furthermore, since heredity includes a series of fundamental \atal processes such as assimilation, growth, division and differentiation, there is something primitive and naive in the view that this most general process can be localized in one specific part of the cell, something which recalls the long-past doctrine that the life was located in the heart or in the blood, or the ancient attempts to find the seat of the soul in the pineal gland or in the ventricles of the brain." ^^ This passage contains several well-sent shafts not only against chromosomal element alism, but against the elemen- talist standpoint generally. And I must recur again in con- nection with it, while the facts of egg organization as pre- sented by Conklin are fresh in mind, to the perception, indicated in previous chapters, that the physical-chemistry conception of the cell must be extended to the organism. If Evidence from Metazoan Germ-Cells 31 Conklin once sees the full force of tliis contention, he will, we may hope, be ready to let go entirely of the idea that the facts of cytoplasmic organization must be "harmonized with the nuclear inheritance theory." ^^ He will then see that there is no more necessity for harmonizing the facts of cytoplasmic organization witli the nuclear inheritance tlie- ory than there is for harmonizing the facts of nuclear or- ganization with the theory of cytoplasmic inheritance. REFERENCE INDEX 1. Ballowitz 255 2. Wilson, E. B. ('00) 135 3. Ballowitz 277 4. Oliver 489 5. Oliver 479 6. Casteel 646 7. Conklin ('05) Ill 8. Conklin ('05) 11 9. Conklin ('05) 21 10. Conklin ('05) 114 11. Conklin ('05) 101 12. Conklin ('08) 90 13. Conklin ('08) 92 14. Conklin ('05) 102 15. Crampton ('99) 48 16. Conklin ('05) 101 17. Conklin ('08) 98 18. Conklin ('15) 162 19. Conklin ('15) 163 Chapter XV EVIDENCE FROM SOMATIC HISTOGENESIS IN MULTICELLULAR ORGANISMS Ayl/ E must now give the greatest possible concreteness ^ '^ to the general truths stated bj Conklin that growth is the result of the interaction between nucleus and cyto- plasm and that heredity includes such fundamental vital processes as assimilation, grow^th, division, and differentia- tion. But the one and only way, I again insist, to attain concreteness and certainty in the matter is through a maxi- mum of observation coupled with a minimum of inference. That is, the goal must be reached mainly by direct study of the anatomical, histological and physiological transforma- tions through which hereditary attributes are produced. The issue can be met squarely only by a still further considera- tion of what we actually know about the participation of all sorts of elements of relatively undifferentiated cells in the production of obviously hereditary parts. The study of interactions between nucleus and cytoplasm and of as- similation growth, etc., in germ-cells is not enough. What we have seen in preceding pages about the development of organs in the protozoa and in spermatozoa is that much toward the end sought. Our task now is to consider the local transformations by which structures are produced in multicellular organisms, especially in those which develop from eggs. The Mitochondrial Theory of Heredity This task may well begin by examining the recent efforts to locate the "hereditary units" in the mitochondria of the 32 Evidence from Somatic Histogenesis 33 cytoplasm instead of in the chromosomes. This effort Is just as misdirected as is the effort to make chromatin the sole hereditary substance. According to tlie organismal conception, all life phenomena, including those of inheri- tance, consist in the activities and interactivities of an enoraious number of substances and units and forces, all of which, in exhaustive analysis, arc dependent ui)on the organ- ism as a living whole. It is, therefore, as futile to hiuii in one comer as another for the physical basis of heredity in an exclusive and more or less metaphysical sense. Any one who has grasped this idea will know beforehand that the proposal to make mitochondria fully explain heredity is doomed to failure no less certainly than was the proposal to make chromosomes or any one kind of cell element play such a role. But h3'potheses, the falsity of which might liave been seen before they were tested, may still be useful. If those who propose them can be convinced of their fallacy in no other way than by testing them then it is better that they should be tested even though much time and labor be given to the task. Again, the evidence brought out which dis- proves an hypothesis may be highly useful in establishing some alternative general view. This result has been espe- cially striking in the case of the mitochondrial hypothesis of hereditary substance. By bringing the cell-body back into the field of interest, from which it had been largely excludi-d so far as heredity was concerned, by the nuclear inheritance theory, the mitochondrial hypothesis has resulted not merely in proving that mitochondria are not bearers of heredity in the elementalist sense, but that in a rational sense they are sometimes rather closely concerned in tlie production of hereditary structures; and, of even greater importance, that still other cytoplasmic material is likewise so concernrd. The only reason why the mitochondrial theory of hered- ity is less interesting than the chromatin theory is that there is so much less obsei-vational evidence in support of it. 34 The Unity of the Organism In fundamental principle the one is no more and no less acceptable than the other. Any half plausible suggestion that a particular minute, obscure part of the germ-cell may be a "bearer of heredity" seems to endow that part with a peculiar fascination to biol- ogists who haA'e the elementalist habit of thinking, and this secures to it an inordinate attention until the untenability of the hypothesis is so overwhelmingly proved that even the most credulous are forced to abandon it. Several biologists have recognized something of the state of mind here indicated without, however, perceiving its real meaning. Thus in a review of the work of Meves, which will be examined presently, we read: "the new interpretation which Meves gives at this time indicates that many are still dissatisfied with the all-sufficiency of the [nuclear] theory, and are eagerl}^ seeking and grasping, as it were, the first visible sign of any other substance which may serve to carry the hereditary qualities." ^ The remark to be made about any statement of this kind is that the real though usually unperceived ground of dissatisfaction is not with the all-sufficiency of the nuclear theory of heredity, but with the all-sufficiency of any theory that attempts to local- ize the function of carrying heredity in some small, specific fraction of the germ-cells ; and that the attitude which Doctor Payne well characterizes as "eagerly seeking and grasping" which has marked so much of recent search after the physical basis of heredity, has a large measure of genu- ine illusion in it. Inspired by the ages-old, alluring belief that an imperceptible final cause and explanation is hidden somewhere within or behind whatever is grossly sensed, the pursuit becomes "eager and grasping," which is another way of saying that it becomes more or less irrational and fitful. The truth of these remarks is rather strikingly exempli- fied in the short, somewhat feverish history of the mitochon- Evidence from Somatic Histogenesis 35 drial theory of heredity. The meager ()l)servati()iial support for the hypothesis that tliese ])artieuhir cell ineiiihers are generally bearers of heredity relieves us from the necessity of examining it in any such detail as we examined the chro- mosome theory. But there are several things al)out it of so much importance that we must look into it somewhat. The name mitochondria was first used by IJenda for a "new cell organ, perhaps serving a specific function." Benda's original view was that the function served is that of the motility of the cell. But in a later publication he presented observations which seemed to him conclusive proof that the mitochondria of the sperm are situated in parts of it which enter the Qgg at fertilization. This last suggestion gave an added impulse to the study of the bodies occurring In the c3''toplasm and soon many new names were applied to them, for they were soon found to present differences in size, shape, and reaction to chemicals. It seems, however, that the present state of knowledge justifies us in applying to them all the one term, mitochondria, though without Im]>ly- ing that they are all exactly alike. They may be held to be generically alike but specifically different. The first investigator to set up definitely the hypothesis that cytoplasmic elements of this class are bearers of hered- itary qualities seems to have been Meves. Only a few of the very many investigations since devoted to the subject can be noticed, these being selected for their bearing on particular aspects of the problem. In the first place, the position of ]\Ieves himself is im])ortant. Accej)t- ing the assum])tl()ns formulated by (). Ilertwig in 1S7.") of a "substance which carries over the begimiings (Anlagen) of the parents to the child," " and that "this substance exists (in the germ-cells) In an original, histologically uiidiffVren- tiated condition";^ and adding his own reflection that not all the cytoplasmic parts of the spermatozoon ( for example, the axial fiber of the tail) possess inheritance potencies, lie 36 The Unity of the Organism advanced the hypothesis that the mitochondria answer the conditions of Hertwig's theory for the cytoplasmic part of the male, though probably not of the female ge'rm-cells. Thus Meves reached the rather attractive conception that ^'heredity is accomplished through protoplasm and nucleus together." ^ Were we to know no more than this about his theory we might suppose his position to be that of a genuine integrationist. However, his very next sentence does not permit us to question any further the orthodoxy of his ele- mentalism. "The qualities of the nucleus," he says, "are carried over by the chromosomes, those of the plasma by the chondriosomes." ^ In other words the working together of nucleus and cytoplasm which he conceives is not of the sort which makes the part played by each contribute to all the results, but that one set of elements produces its partic- ular part of the total effects, while another set produces another part of the effects. The Mitochondrial Theory Tested by the Ontogeny of the Spermatozoa The utter inadequacy of this hypothesis is shown by some of the same evidence which revealed to us the inadequacy of the chromatin theory, namely that when we come to study the histogenetic processes by which innumerable hereditary attributes are produced, we find portions of the cytoplasm other than the mitochondria taking the leading part in the production. Perhaps no single one of the many instances examined by us of cytoplasmic participation in the produc- tion of attributes refutes Meves' hypothesis more complete- ly and instructively than that of the developing sperm of the fowl tick already described. We have already examined this case as one of special weight in proving that the cell-body, in contradistinction to the nucleus, is hereditary substance. Now we must see the conclusiveness Evidence from Somatic Histogenesis 37 with wliicli this particular ontogeny disposes of the mitochondrial hypothesis of heredity so far as tiiis case is concerned. Recurrence to the descri))tion and figures (42 a, b, c, d, e, f ) will recall that the mitochondria^ widely distributed through the cyto- plasm in the early spermatocyte {mi.) assemble into a rather sharply defined ring-shaped mass (m.r., figure l-^b) as the cell transformation proceeds, and finally take a position in the devel- oping sperm about as remote as they can get from some of the most actively and fundamentally changing parts of the organism. {mi., figures 42 e, f, g). There is no more possibility of explaining the development of many of the parts of this sperm, the outer sheath, for example {o.t., figures 36e and f ) as due to the influence of the mitochondria than as due to the influence of the nucleus. And I point out again for the hundredth time what the real issue is here. The observations certainly do not exclude the possibility that the mitochondria exercise some invisible influence on the development of, sav, the outer sheath. There may be or there may not be such an influence. But the observations do show conclusively that cytoplasmic portions of the cell other than mitochondria are operative in producing the outer sheath. It should be said in concluding this reference to tlie sperm of the chicken tick that Casteel finds the mitochondria located finally in the end of the sperm opposite that which contains the nucleus; and that this end goes ahead in locomotion, the motion being pro- duced by a circlet of mobile processes at this end. From this he believes that the contractile elements are mitochondrial in origin. The conjecture that the mitochondria of the spermatocyte take part in producing the motor elements of the sperm tail is perhaps strengthened by the observations of other students, notably Lewis and Robertson. These investigators were able to follow tlie mito- chondria in the ontogeny of the living sperm directly into the tail, where they transform into two equal threads situated along- side the axial filament. Tlie Mitoclxondrial Theory Tested hi/ Histogenesis If this hypothesis that mitochondria in developing sperm cells give rise to the motion-producing structures of the sperm tail, then the mitochondria would be genuine "inlieri- tance material" for these particular elements, the hereditari- 38 The Unity of the Organism ness of the motile elements being especially striking in the case of the chicken tick sperm from the fact that the mode of locomotion in this spermatozoon is almost unique. But while the case of mitochondria and other non-nuclear parts of the cell in the development of the spermatozoa, ought to be conclusive that although mitochondria can not be "hered- itary units" in any general sense, they, as well as other cytoplasmic parts, may contribute to the production of hereditary structures, yet it would not be so accepted, prob- ably, by the most exacting theorists because such biologists would not allow that a spermatozoon, being unicellular, can have organs and parts which are subject to heredity "in the strict sense" (i.e. in the sense of the definition of hered- ity set up by these persons). We must, consequently, pro- ceed to the specific task of this section ; namely that of considering what is known about the part played by mito- chondria in the histogenesis of hereditary structures in multi-cellular organisms. Nearly all the studies centered upon the question of whether the mitochondria are bearers of heredity have gone on the assumption, quite inadequate according to my view, that the problem is to be solved by ascertaining whether or not the bodies are persistent cell organs, take a definite part in fertilization, and are contributed in equal quantity by the female and male germ-cells. In other words the assump- tion has been that the same criteria which have been relied upon to prove that chromosomes are bearers of heredity, must also be applied for deciding whether or not mitochon- dria have the same office. But numerous studies have also aimed to follow the mitocliondria in the genesis of tissues, and herein lies the chief importance of investigations in this domain. Not only have they greatly increased our knowledge about the role played by various parts of the cell in histogenesis, notably of the cytoplasmic parts, but they have put us in possession of much precise information Evidence from Somatic Histogenesis 39 as to what "hereditary suhstancL'" is. The results and conclusions tlius far reached are on the whole so diverse, often so conflicting, that any attempt at a general review of them would be useless for this discussion. However, certain of tlie results, actual or claimed, are im- portant. For example, at one extreme it is contended that the mitochondria are the innnediate })recursors of the most distinctive elements of all classes of adult tissues. Thus Meves : "All these differentiations (of embryonic cells into tissue cells) however heterogeneous they may be, arise through the metamorphosis of one and the same elementary constituent of the plasma, the chondriosomes. The chondri- osomes are the material substratum lying at the basis of the processes of differentiation, which become the specific sub- stances of the different tissues." ^ As an extension of this view we learn from Lewis and Lewis and other reviewers that the following tissues are reported on the authoritv of a long list of workers to be produced by the mitochondria: fibrilla?, myofibrilL'c, fibrillje of epithelial cells, corneous sub- stance, secretory granules, fat, leuco-, chloro- and chromo- plasts, the test substance in foraminifera, and various other tissue elements. But several investigators, notably E. V. Cowdry, have shown the inconclusiveness of the evidence on which the con- tention is based that neurofibrils originate from mitochon- dria. "There is no evidence," Cowdry says, "that mito- chondria are transformed into neurofibrils. . . . Tlie mi- tochondria do not show, either by a variation in tluir morphology, staining reactions, or in any other fashion, . . . indications of being transformed into material of dif- ferent chemical composition." * Furthermore, he shows that the mitochondria do not diminish in quantitv in anv way commensurate with the increase of neurofibrils, as thi' ni'U- roblasts transform into ganglionic cells. Eminently worthy of note, as bearing on our contention made some pages 40 The Unity of the Organism back, that cytoplasm itself is hereditary substance, is Cow- dry's detailed description of neurofibrils as a "differentia- tion of the ground substance" of the neuroblasts. And in a later paper the same author makes a strong case of the view that while mitochondria are "associated in some way with the formation of many substances," ^ it is highly im- probable that they transform into them. On the whole the tendency of the latest investigations appears to be to deny that the bodies produce, in a strict sense, any tissue elements. Thus as a result of their quite remarkable studies on mitochondria of living cells Lewis and Lewis say, following the enumeration given above: "The above theories seem impossible to correlate. It seems evi- dent that the mitochondria are too universal in all kinds of cells to have the function of forming any one of the above structures of differentiated tissue, and in the light of what cytological chemistry is known, it appears practically impossible for the mitochondria to form all the cell struc- tures mentioned above. In view of the fact that the mito- chondria are found not only in almost all animal cells but in plant cells as well it seems more probable that they play a role in the more general physiology of the cell." ^ The idea that the mitochondria are primarily concerned with the metabolism of the cell appears to be gaining ground under the present comprehensive and critical methods of investi- gation that are being applied to them. The Untenable Hypothesis that the Cytoplasm of the Ovum is Inheritance Material for General hut not for Special Characters A number of biologists have recently put forward the hypothesis that while the cytoplasm of the egg-cell may be "hereditary material" for certain of the general attributes of the organisms, chromosomes "carry" the hereditary, Evidence from Somatic Histogenesis 41 of tlio more specific attributes. This conception has arisen from a considerable range of observations to the effect that for quite a time in the early ontogeny of many animals some of the attributes of the embryo can be seen to come directly from the cytoplasm of the egg. Thus both Driesch and Loeb have taken special notice of tlie fact tliat, as expressed by Loeb, "when the ]iroto])lasm of the vgir ])()ssesses a strik- ing pigment the larva will possess tlie same for some time at least"; and that "if such an Qgg is hybridized with tlie sperm of a form whose egg is unpigmented, the larva will, of course, possess a 'maternal' quality which is due solely to the protoplasm ( Driesch )".^^ And in the same connec- tion, Loeb continues : "It is obvious, tlien, that during the first stages of development an influence of the protoplasm upon heredity may make itself felt, which will disappear as soon as the protoplasm of the egg has been transformed into the tissues of the embryo." One of the cardinal questions we have to consider may be formulated in connection with tliis last quotation: Have we a right to assume that because an obvious influence of the protoplasm upon heredity dis- appears on the transformation of the protoplasm into tis- sue, therefore all such influence of the protoplasm ceases.'^ To answer this question through observations upon the protoplasm of the cells concerned just before, during, and just after the transformations is exactly the central aim of this section. I can not refrain from making use of another sentence from Loeb to aid In defining the problem more clearly. "It does not seem to me," he writes, "that a discussion as to the relative influence of protoj)lasm and nucleus upon heredity will prove very fertile, but that It is necessary to transfer this problem as soon as possible fi'oni the field of histology to tliat of chemistry or physical chcni- istry." ^^ I quite agree that "discussion as to the relative influence of protoplasm and nucleus ii])()n heredity" can not be very fruitful. But the grounds of my ske])tlclsm are 42 The Unity of the Organism widely different from those of Loeb. According to my view, the question is not one to be settled by discussion at all, but by observation coupled with a measure of consistent reasoning. Assuming that I am right, to "transfer" the problem "from the field of histology" if this really means, as it seems to, that the problem should be taken away from histology, no matter whether to the field of chemistry or any other, would be to remove it all the further from ob- servation and plunge it so much the deeper into discussion. I have not the slightest doubt that chemistry, especially biochemistry pursued on the principles of physical chem- istry, will have to be made large use of before the fullest possible understanding of the mechanism of heredity is reached. But this use will have to go hand in hand not only with morphological studies on germ-cells, but as well on hosts of cells during the whole ontogeny. Chemical in- vestigation will have to supplement, it cannot supplant, it cannot even lead, histogenic investigation. If there is one thing made more positive than any other about heredity by modern study of the subject, it is that heredity is some- thing which pertains to the smaller taxonomic grades of organisms, races, varieties, species and so forth. It would seem, accordingly, that hardly any suggestion for the study of heredity could be wider of the mark than one to trans- fer it from the only field which makes any pretense of in- vestigating the details of development, and taking it into a field like that of physico-chemical activity, w^hich is no- toriously devoid of the very attributes without which there would be no such thing as heredity. Having once ascer- tained by observation as much as possible about how hered- itary attributes are actually produced, it will then be in order to leam as much as possible about the chemistry of the processes. Chemistry can do its share in solving the problems of heredity after and not before histogenesis has done its share. Evidence from Somatic Histogenesis 43 Conklin lias expressed more definitely than any other biol- ogist with whose writings 1 am acquainted, the idea men- tioned above, that cytoplasm "influences" heredity in early ontogenetic stages, and also influences adult attributes of the major taxonomic groups, but })ecomes inoperative in the later stages of development, the heredity of these being transferred to the nucleus. He says, "/// short, the c(j(j cytoplasm fixes the general type of development and the sperm and egg nuclei supply only the details.^* And fur- ther: "We are vertebrates because our mothers were vertebrates and produced eggs of the vertebrate pattern ; but the color of our skin and hair and eyes, our sex, stature, and mental peculiarities were determined by the sperm as well as by the ^gg from which we came. There is evidence that the chromosomes of the Qgg and sperm are the seat of the differential factors or determiners for ]\Iendelian char- acters, while the general polarity, S3^mmetr3% and pattern of the embryo are determined by the cyto])lasm of the iigg.''^ 11 jf ^^Q points in this last quotation be viewed in the light of a large mass of relevant evidence not usually taken into account in recent discussions on lieredity, and if strict consistency in the use of terms be maintained, the general conclusion will be quite different from that stated by Conklin. These two points, the concej)tion of "differen- tial" and of "determiner," must now receive attention ; but first I will illustrate my position by a case presenting the kind of evidence to which I have referred. Species Attributes in Single Cells of Ail id t Organisms In general, this evidence comes from the field of histology, or more strictly histogenesis. The most convincing, because the most direct, evidence from this source is that })ertaiiiiiig to the development of hereditary structures in adult nieta- zoa and metaphyta. The structures in such organisms 44 The Unity of the Organism which are the most indubitably hereditary are those which distinguish the smaller but yet definite taxonomic groups. A little consideration will convince one that about the most crucial cases would be those in which the development of differential attributes could be traced directly to cell struc- ture and development. It so happens that vast as is our knowledge of histogenesis, the part of it which answers directly to the requirements here laid down is by no means large. The Spmules of the Ascidian Genus Styela The best instances I have been able to find are super- ficial appendages in some animals and plants, so small that they consist of a few cells or even of a single cell. One strik- ing instance of this sort has come to light in my own studies. a. M.- -n FIGURE 44. SPICULE CELL OF STYELA YAKUTATEXSIS ( AFTER HUXTSMAX). n., nucleus. It is that of the minute spines which cover the inner surface of the branchial siphon in some species of the ascidian group of Styalids. Huntsman first called attention to the fact that each spinule is a single cell, and that at least in some cases the structures furnish differentiating attributes for species. Miss Forsyth and I have reexamined the point for Styela montereyensis and S. yakutatensis, and are able to Evidence from Somatic Histogenesis 45 confirm Huntsman's results. As Huntsman luul opportun- ity to study the matter in a larger number of species than Miss Forsyth and I have had, the following description is taken largely from his paper. Figures 44a, 1), 45, 46 are from Huntsman and fimire 47 is from Hitter and Forsvth. By comj)aring figures of what may be called the dorsal view (figures 44a, 45, 46) witli the side view (figure 441)) it is seen tliat the distinctive feature about the cell whicii con- stitutes the spinule is a shield-like plate on one side of the somewhat elongated cell, the distal end of which |)rojects more or less beyond the cell body, the whole resembling to FIGURE 45. SPIXULE CELT- OF STYELA Pr.ICATA (aKTKU HUXl'S.MAX). some extent the end of a finger with its nail. The shield is harder than the rest of the cell, and is probably com- posed of the same material as the general "test" of Ascid- ians, animal cellulose. The spinules are so placed that the basal portion is embedded in the surface layer of the test on the inside of the siphon, the shield being on the free side of the cell with its free edge ])ointed toward the lumen of the siphon. The specific attributes furnished by the spinules depend upon the shape and structure of the shields. The free edges may be truncate (figure 44, S. yakuta- tensis), or long-pointed (figure 46, S. grech\i/i), or low- conical (figures 45, 47, ♦S'. plicata, S. montercifcnsis). Again the edge may be smooth (figures 46, 47, S. grccUyi 46 The Unity of the Organism and S. montereyensis) , or it may be serrate (figures 44, 45 S. yakutatensis, S. plicata). Viewing this case in the hght of considerations put for- ward on the preceding pages, the pertinent queries about the heredity of the shields almost ask themselves : What is FIGURE 46. SPIXULE CELL OF STYELA GREELEYI ( AFTER HUNTSMAN). the "inheritance material" that causes the sliield to be short and truncate in S. yakiitatensis and long-pointed in S. greeleyi; or that explains the serrated edge in S. yakiita- tensis and S. plicata as contrasted with the smooth edge in S. montereyensis and S. greeleyi? Is the "seat" of that ma- terial in the cytoplasm or the nucleus of the shield-produc- ing cell? Unfortunately we have no direct obsei-i^ational infonnation about the genesis of the spinules. But the Evidence from Somatic Histogenesis 47 indirect evidence whicli bears on the point favors over- wlielmingly the view that the cytoplasm is chiefly responsible for the shield. Huntsman supposes the sj)inules to be de- rived from the cells of the celhilose tunic characteristic of ascidians. He may be right in this; but it may be, too, tljat they are derived from the epithelial lining of tlie sipluni. The matrix of the cellulose tunic is undoubtedly largely if not wholly produced by the ectodermal cells. It is usually held to be secreted by these cells ; but in some cases, in FIGURE 47. SPIXULK C'EIJ. OF S'l'YEI.A MOXTEREYEXSTS (aFTER RFTTER AND FORSYTH ) . Perophora for example, a portion of the cytoplasm of the cells seems to become transformed into the cellulose. The process of transformation can be particularly well seen in the cells which line the branchial siphon of developing bhis- tozooids as shown in figure 32, plate III of my memoir.' - The ])arts of the cell-bodies turned toward the cellulose are here long drawn out and the protoplasm gradually becomes indistinguishable from the surrounding cellulose substance in which it is imbedded. If now we imagine this proto})lasm to transform not into the characteristic cartilage-like cellu- lose mass spread over nearl}'^ the whole surface of the body, that from innumerable cells fusing into a connnon mass, hut each cell to retain its individuality, its protoplasm becoming the shield of a spinule, we should have what these styelids 48 The Unity of the Organism actually present. But whatever be the cells which transform into the spin- ules, all the available evidence indicates that the cytoplasm is the chief source of the shield part of the spinule. The possibility is not excluded that the nuclear chromatin also plays some part in the development. Indeed investigations, notably those by Duesberg on the ascidian egg made since "cytoplasmic inclusions" have come into prominence are distinctly favorable to such an hypothesis. But this is very far from proving that such chromatinic influence, assuming it to exist, reduces the cytoplasm to pure passivity. In the light of what is here set forth let us examine the view expressed by Conklin and quoted above that the o^gg cytoplasm fixes the general type of development, while the nuclei of ^gg and sperm together "supply only the details." The examination should be the more cogent from the fact that Conklin's idea was based largely on his investigation of ascidian eggs, some of which pertained to the very same genus, Styela, as do the spinules just described. The reader should not fail to notice that both Conklin and myself are dealing with single cells, he having to do with egg-cells, while I am concerned with spinule cells. Nor should the fact be lost sight of that these two categories of cells stand at about opposite extremes in the life career of an individual Styela, the ^gg being at the very beginning, while the spinule is produced at or near the completion of adulthood. Since, however, both cells possess attributes distinctive of the species, there can be no more "filling in of details" at one end of the series than at the other, so far as concerns the differential attributes under consideration. Now comes the main point. The differential attributes of the egg-cell and early embryo, their "polarity, symmetry, and pattern," are "determined by the cytoplasm," to use Conklin's own words. What is the evidence that these attri- butes are thus determined? That of direct observation. Evidence from Somatic Histogenesis 49 as the examination of Conklin's work has shown. But if on the basis of such observation it can be asserted tliat attri- butes of egg and early embryo are determined by the cyt(j- plasm, how escape asserting that the same sort of evidence touching the production of the athilt attributes, those per- taining to spinule cells, are likewise determined by tlie cyto- plasm ? It was remarked above tliat if all known relevant facts were taken into account and consistency in terminology be maintained, Conklin's statement to tlie effect that we are vertebrates because our mothers were vertebrates and pro- duced eggs of the vertebrate type, but that our species and racial characters, color of skin and hair, and so forth, are determined by the chromatin of both parental germ-cells, would have to be greatly modified. We are now in position to see what modification is necessary. Although the state- ment is undoubtedly true that we are vertebrates because we develop from vertebrate eggs, the implication that the attributes which identify us with the human species and the Caucasian race are explained, so far as heredity is con- cerned, by the chromatin of the geiTn-cells, whether male or female or both, is not in accordance with all the observed facts bearing on the problem. The same kind of evidence on which the assertion is based that the embryonic charac- ters are determined by the cg^ cytoplasm, requires the assertion that skin and other adult characters are deter- mined by the same means. This leads to the remarks we have to make about con- sistency in the use of terms. The critical reader will hardly have failed to notice the difference in application of flu- word "determined" as used by Conklin in the quotation we are examining. When it is said that the color of skin, hair, stature and so on are determined by the genn-cells, the determining act or condition is far removed from that which is determined, and no direct causal connection be- 50 The Unity of the Organism tween the two is established. On the contrary in the state- ment that the polarity, symmetry and pattern of the Qgg are determined by the cytoplasm, the determination is im- mediate and observed. Manifestly in a literal sense "de- termined" is proj^erl}'^ used in the second connection but not in the first. The cytoplasm is operative on the spot, so to speak, in the second case. It is concerned with an immedi- ate result. The germ-cells on the other hand are not really determiners. They are not concerned with, an end result, but are if anything instigators of a long developmental series at the far end of which appear the attributes in question: skin, color and the rest. If this case of spinule production stood alone as an instance of specific characters in adult animals traceable to cytoplasmic activity of individual cells, it would be a rather small base on which to erect a general argument in favor of cytoplasm as inheritance material. But it does not stand alone. Indeed, the company to which it belongs will almost certainly be found to be legion when systematic investigation of the subject shall have been made. The Spictdes of Sponges and Other Invertebrates I will cite a few more cases. In several widely separated groups of animals, spicules, usually either calcareous or silicious, are present in some of the tissues. These are often produced by one or a very few cells, and often, too, their shape, size, and probably other attributes differ from species to species even of the same genus. The spicular system reaches its greatest development and has been most studied in sponges. "The spicules of sponges," writes Sedgwick, "in the diversity, symmetry, and intricacy of their form, in the perfection and finish of their architecture, constitute some of the most astonishing ob- jects in natural history." ^^ Figure 48 gives a hint of the Evidence from Somatic Histogenesis 51 facts on wliicli this statement is based. Altliougli the pr()l>- lem of wliat all these s])icules are for does not dlreetly con- cern us, indirectly it does, as the following further remarks of Sedg^vick will indicate. "While it is pretty clear," he says, "that the main function of the skeletal structures is the support and protection of the sponge body, it is by no means easy to give explanations of the diversity and com- FIGURE 48. SPICULES OF SPOXGES (aFTEK LAXKESTfUl) . plexity of form which they present. The form of the megas- cleres is probably connected with the form of the canal sys- tem with which they are in relation (F. E. Schulze) ; but tlu" form and even the existence of the microsclcres defies any reasonable explanation." And then comes this statement, highly significant for almost any discussion of heredity : "By some spongologists the small spicules ari' regarded as functionless, and as having on that account a greater value for classificatory purposes." ^^ If any one wishes to be convinced of the extent to whlilj the spicule forms differ with different species, he should 52 The Unity of the Organism consult such systematic monographs as those of Schulze and Sollas in the reports of the Challenger Expedition. A picture of such a group of spicules as that shown in figure 48 reminds one of pictures of ice crystals he has seen; and the question may well be raised, Are not these spicules in reality crystallization forms, and hence as devoid of hered- itary significance as are snow flakes? The fact that the form they have depends on the particular group of sponges to which they belong, i.e., that they follow the rules of biological taxonomy, is very strong evidence that they are FIGURE 49. DEVELOPMENT OF A SPICULE (aFTER LANKESTER). genuine organic productions, and not mere crystallizations. And the further fact that they follow this rule even though many of them appear to have no functional significance in- dicates that their particular forms are due to heredity and not to modeling by extraneous influences in each individual sponge. But we are not left to such general evidence for support of the supposition that they are true organic products and subject to heredity. Their development has been studied by several zoologists and the results leave no doubt about their nature so far as this point is concerned. A single instance will be enough for our purpose, but it should be remarked that many others could be given. This is taken from the excellent summary of what is known about sponges written by Minchin for Lankester's Treatise on Zoology. "To form a triradiate spicule three cells migrate into the parenchyma from Evidence from Somatic Histogenesis 53 the dermal epithelium and become arranged in a trefoil-like figure (Figure 49). The nucleus of each cell then divides into two, in sucli a way that one nucleus is placed more dee})ly and one more super- ficially. Between each pair of sister nuclei a minute sj)icule ray appears_, the three rays being at first distinct from each other but l-r. Sys^. FIGURE 50 SEE 49. soon becoming united at the center of the system (Figure 50 tr. syst.). As the rays grow in length the protoplasm of each actino- blast becomes aggregated around each of the two contained nuclei and finally more or less completely segmented off to form two formative cells, of which the one placed more internally travels to the tip of the spicule ray^ while the other remains at the base FIGURE 51 SEE 49. b.f.c, basal formative cell, tr.syst., triradiate system. (Figure 51, b.f.c). The apical formative cell sooner or later dis- appears, returning, apparently, to the epithelium. The basal formative cell remains at the base of the ray (Figure 51), until this portion is secreted to its full thickness. It then migrates slowly outwards along the ray, and in the fully formed spicule is found adherent to the extreme tip." 54 The Unity of the Organism That such a mode of development is entirely foreign to crystal production hardly needs to be remarked. But if further proof to the same effect were demanded^ one other strong piece of evi- dence is the fact that most of the spicules are not composed of inorganic substance alone but have a core of organic matter. Although the technique for the examination of cytoplasm de- veloped during these last years has not, so far as I know, been applied to the spicule-producing cells of sponges, we can be reasonably sure from the study of other secretory cells what the general results will be when such application sliall have been made. They will bring out numerous details not now known of how both the nucleus and the cytoplasm act during spicule pro- duction. Surely it is not necessary for me to dwell again on the main point of the eyidence here presented. The nuclei of the spicule-fomiing cells may take an active part in pro- ducing the spicules. Indeed from our general knowledge of nuclear activities, illustrations of which were given in an earlier chapter, it is probable that such will some day be demonstrated to be the case. But the proof of nuclear activity in spicule production will not he disproof of the already observed cytoplasmic activity in spicule production. Other animals that may be mentioned in which spicules are produced in much the same way and have the same taxo- nomic diversity and constancy are the alcyonaria among coelenterates, the holothurians among ecliinoderms, and some of the compound ascidians, particularly of the family didemnids. Relative to the specificity of the structures in holothurians, we have this piece of significant information: "These calcareous bodies are of great value to the system- atist in classifying the smaller groups, such as genera and species. Although their general characteristics are fairly similar within the several families, the different shapes of spicules are not sufficiently constant to be used as diagnos- tic characters of such large divisions." ^^ In other words, so far as these animals are concerned, should it be found. Evidence from Somatic Histogenesis 55 as it almost certainh' will be, that Hic cjto])lasni is "hered- itary substance" for the production of s])iciih's, tlic reverse of Conklln's generalization that the cytophism dctcrniiues the larger taxonomic features of animals while chromatin is the seat of the inheritance factors for "fillinir in details" turns out to be true. Species-marking details arc just what we are able to see the cytoplasm fill in. The "Hairs'' of Higher Plants For a few more instances of species characters in multi- cellular organisms brought down to single cells, we turn to the plant world. FIGURE 5-2. FIGURE 53. FIGURE 54-. FIGURE 52. TRICHOIMES OF PAPAVER ORIENTAI.E (aFTER CANNON ). FIGURE 53, TRICIIOMES OF P. PILOSUM ( AFTER CANNON ). FIGURE 54. TRICIIOMES OF P. SO^IXIFEHr^I (.MTrH CAN SOS ). The "hairs" or trichomes borne on the leaves, flowers and smaller stems of innumerable flowering plants are usually composed of only a few cells, so that the characters they have are often referable to the individual cells. Can- non has lately investigated these structures in several gr()U])s of plants, and while he was not aiming at the particular question now occupying us, some of his results are (jiiife to the point for this discussion. An exami)le of particularly distinct specificity of the hairs Is ])resented in the following: "The trichomes of the three species | of p<>pi)y | are similar 56 The Unity of the Organism in form and size, but they are unlike in quality of rough- ness. In Papaver orientate (52 a, b) and Papaver pilosum (53 a, b,) the distal ends of the superficial cells project be- yond the general surface of the trichome and turn out at a rather acute angle. In Papaver soTnniferum, however, these cells did not extend beyond the general surface, with the effect that the trichomes of this species are smooth (fig- ure 54 a, b)." ^^ This is especially instructive because the attribute in question pertains to the shape and position of cells, and not to differentiation within the cells. There, consequently, is no room for even a reasonable surmise that the attribute is explained by the chromatin instead of the cytoplasm. Even though the account gives no information about the position and behavior of the nuclei of the cells, it is hardly con- ceivable that any one would maintain that the substance itself of the cell-tips is not the main factor in the out- turning of these tips characteristic of Papaver orientate (figure 52 a, b). Dealing with quite another type of trichomes, those of the walnut. Cannon writes: "A character which easily dis- tinguishes the short secreting trichomes of Jwgtans cati- fornica from those of Jugtans regia or Jugtans nigra is the length of the head-cells." ^'^ Both drawings and tables of measurements of the heads showing lengths and diameters are given to bring out the positiveness of the distinction. Furthermore, details of cell division and cell structure dur- ing the development of the trichomes are furnished ; so the visibte evidence that the cytoplasm is "inheritance material" in this case is beyond question. What the invisible evidence may be remains for further investigation to discover, but of one thing we may be sure: no matter how many facts of development now invisible may later become visible they will not destroy the validity of the present visible evidence. How far it would be possible to go on pointing out specific Evidence from Somatic Histogenesis 57 characters of plants that are referable to Individual cells I do not know; but judging from the instances that come to view even in my limited knowledge of the subject It might be carried to an almost indefinite extent. Anotlier instance which I recall from the experience of my student days is the case of mosses. The serration of the leaves, I remem- ber, was one of the features relied upon for generic and specific characteristics, and I also remember that the indi- vidual teeth often if not always consisted of one or a very few cells. Cell-wall Structures in Higher Plants That the cell-wall is a structure of great importance in plants is known to everybody ; and the veriest tyro in plant histology has learned something of the enormous variety and definiteness of character in different tissues and dif- ferent kinds of plants presented by this part of the cell. A very brief reference to two plant structures, pollen- grains and wood tissue, will be, perhaps, a sufficient re- minder of what there is for us in this domain. A typically formed pollen-grain is a minute spheroidal body containing two cells, one known as the antheridial or germinative cell and the other as the sterile or vegetative cell. The wall of the grain consists of an outer coat, the exine, and an inner, the intine. The elaborateness of structure which these coats may reach is astonishing if regarded in the crepuscular liglit of the theory that cells are "simple" things. The most dis- tinctive thing about the pollen-grain is the pollen tube which is produced on one side of the grain and througli which the antheridial cell reaches the ovule in fertilization. The taxonomic variety which is our main interest just lure pertains largely to the sculpturing of the surface of tlu' exine and to the structure of tlic exine at the point where the pollen tube will break through. It is well known to botanists that the "spikes, warts, ridges, combs, etc." of 58 The Unity of the Organism the surface of the grains are in general definitive of taxo- nomic groups of plants. And concerning the places of emergence of the pollen tube we read : "The number of these peculiarly organized points of exit is a fixed one in each species, and often in whole genera and families." ^^ As to 'the way these various structures are produced we have this very definite statement: "The sculpturing upon the outer surfaces of the spores of mosses and ferns and the corresponding pollen grains of the Phanerogams can in most cases be attributed to the activity of the protoplasm surrounding the developing spores." ^^ That the main tissues of plants present taxohomic char- acters is amply illustrated in the wood-tissues. The facts concerning these tissues have been almost forced into prominence by the needs of fossil botany, though they have also been much studied as a part of ordinary plant mor- phology. The section on fossil wood in Zittel's Handbook of Palaeontology is a considerable resume of knowledge in this field, and contains numerous statements and figures which bring out impressively the general truth of the specificity of the tissues of trees. After necessary allowance is made for the strictly botanical unsatisfactoriness of many of the species and genera recognized by palaeobotanists, it is not doubted, so far as I know, that on the whole the kinds of tissue they describe do in reality represent different kinds of trees. A single illustrative quotation will serve to make concrete what is here dealt with in general terms : "The phloem segments, like those of the xylem, are divided by few-seriate pith rays into rather regular two- to four- seriate rows of cells made up of thin-walled, small-celled elements in the trunk of Zamia floridana, etc., and Stan- geria. But ... in the trunks of Cycas, Dion, Encepha- lartos, Macrozamia and doubtless most cycads, as likewise in the Cycadeoideae, sclerenchymatous elements are more or less numerously and regularly interspersed among the Evidence from Somatic Histogenesis 59 row cells, thus giving much more strength to the stem," ^^ And the author goes into considerable detail in discussing the presence and tlic absence of "wood tracheids," "scahiri- form pittings," "border pits," "spirally tliickened walls" and "sieve tubes" in tlie genera Zamia, Cordaites, Stanfjeria and Cycas. That this well-nigh endless variety of character of the cell- wall in adult plant tissues is due to the activity of the cell protoplasm appears never to be questioned by botanists so long as they are dealing with the actual structure and development of the wall. "The cell-membrane is produced by the protoplasm," we read in the section on morphology in the Lehrbtwh der Botanik by Strasburger, Jost, Schenck and Karsten (11th German edition) this section being from the pen of Strasburger himself. Tliis simple, unqualified statement of fact by Strasburger is the more noteworthy because, as we saw in another connection, he has been one of the extremists on the chromosome dogma of heredity. Reading his statement that the cell-membrane is produced by the protoplasm, with the indubitable fact in mind that this membrane presents innumerable characters which are taxonomically definitive, and hence are hereditar}^ according to the best criteria we have of hereditary characters, it seems impossible to avoid seeing that it implies an irrec- oncilable contradiction of Strasburger's often-repeated view that the chromosomes are the sole bearers of heredity. To round out the primarily factual part of this discussion two questions remain to be considered: first, that of heredity in the main classes of tissues of nudticellular organisms; and second, that of the results being reached by tlie latest methods of cytoplasmic study on the behavior of different portions of the cells in tlie histogenesis of these tissues. What is implied in these two questions can be made clear by a special case. Is the minute structure of striated nuisele tissue, for example, subject to heredity.^ If so, are the 60 The Unity of the Organism hereditary attributes determined by the chromatin or by the cytoplasm of the myogenic cells? Applying our usual test for hereditary structures, we ask whether or not this tissue presents attributes characteristic of the taxonomic groups, species, genera, families and so on. Here again, while we have a vast store of knowledge about the structure and genesis of muscle tissue in many kinds of animals, only incidentally, as a rule, have the studies been made from the taxonomic standpoint. The Morphology of Striated Muscle Fibers For one series of very recent studies that comes near this standpoint we are indebted to H. E. Jordan. On the taxo- nomic aspect of the matter Jordan writes : "A quite gen- eral consensus of opinion considers them more or less closely related, and ranks them both between Crustaceans and Arachnoids. Limulus muscle, however, is in appearance very much more like vertebrate than like insect muscle ; while the muscle of the marine arthropod Anoplodactylus is of the typical insect type." ^^ Of the numerous differences between the fibers of the two animals compared, reference to two will suffice for our purpose. They concern the so-called M and Z lines found in the light bands of most striated muscle tissue. What Jordan regards as one of the important re- sults of his work on Limulus muscle was the evidence secured that the Z line represents a membrane, as some observers have believed, the specially convincing evidence being the fact that the "line" is attached to the sarcolemma periph- erally and to the nuclear wall centrally. These rela- tions are lacking, he says, in the sea-spider's muscle. The M line, he tells us, is especially well developed and hence easily demonstrated in the sea-spider muscle in some states of contraction, while he failed, as have other students, to detect it at all in the Limulus muscle. ^^ Evidence from Somatic Histogenesis 61 So we come again to the real issue. Assuming the Z membrane to be a cytoplasmic structure, as it has practi- cally always been held to be, are we going to deny that the cytoplasm itself causes the peculiarity of the Z membrane in tlie sea-spider as compared with that in Limidus, that denial being necessitated by the dogma tliat the real "seat" of the difference is the chromatin of the nucleus operating by some invisible "factor" perhaps of the nature of an enzyme? The extent of variety in striated muscle tissue is brouglit impressively to view in such a comparative study as that by Marceau. His main object is not to find differences but to discover whether in spite of structural differences they have similar traits, as if they might all be derived from a single primitive form which has undergone more or less profound modification. Of the many differences which the investigation sought to re- duce to orderliness on the basis indicated, only two will be men- tioned. From an elaborate table of measurements of the diameter of fibers, we find the following results for the sheep and pig: "^ Maximum Minimum Average Sheep 25 fi Sfx 15ju Pig 45 5 20 The other point selected concerns "striated scleriform trans- verse bands" characteristic of the muscle fibers of the vertehrate heart. This time the animals we choose are the liorse and cow. The thickness of the band is jjiven as exactlv the same in thesr two, but the distance between the bands is 1 lO^u for tlie horse and 120/1 for the cow.^* The FliysioJogy of Miiscle Fibers We might go on almost endlessly, pointing out slight hut con- stant specific differences that involve differences in muscle struc- ture, questioning in each case whether the hereditary cause of this difference lies in the cytoplasm or chromatin of the nmscle 62 The Unity of the Organism cells. But such repetition would be useless for the present dis- cussion. Striated muscle tissue is specially favorable for testing hypotheses about inheritance material from the functional side as well as from the structural side. For' example, there are innu- merable differences, larger and smaller, in the limb movements of animals belonging to different species and genera. I know of no observations which precisely connect activities of this sort with muscle tissue; but information concerning the electromotor force in various animals is available. The following on the au- thority of Englemann, taken from Winterstein will serve our purpose. The values are those of the "demarcation current" of galvanic electricity of heart muscle, this current being generated by making a cut surface at the base of the heart and the natural surface at the apex act as a galvanic pile: ^^ Animal species Electromotor force in D. Anguilla fluviatilis 0.0265 - Rana esculenta 0.031 1 Triton cristatus 0.0124 Tropidonotus natrix 0.036 Testudo graeca 0.022 Columba livia 0.0458 Cygnus oler 0.0168 Mus musculus v. albino 0.040 Mus rattus v. albino 0.0446 Lepus cuniculus 0.0o63 These investigations appear to have been made from the stand- point of general physiology, and therefore not to have been car- ried out with the systematic exactness and exhaustiveness de- manded for taxonomic discrimination. We may consequently presume that more searching examination of the same series would considerably modify these results, but we have no reason to suppose that they would eliminate altogether the differences due to the animal species. After due allowance is made for the purely physiological and environic causes which undoubtedly explain a great many of these differences, probably no biologist would hesi- tate to grant that many of them have an hereditary basis. Turning again to the question of the seat of the hereditary Evidencr from Somatic Histogenesis GiJ factors, we are now especially attracted by the functional aspect of the subject. To an unsophisticated physlolog-lst studying the phenomena involved in this question, it would probably never occur that more than one answer is possible. Well-informed as such a physiologist may be supposed to hv on the important part known to be played by the nucleus in the life of the cell, he would undoubtedly take it for granted that the whole nucleus, its chromatin with the rest, con- tributes in some fundamental way to the result. But unless well indoctrinated beforehand with the chromosome dogma of heredity, he would almost certainly be amazed were some one to contend seriously that the cytoplasm is not the material basis of the hereditary peculiarities exhibited. He would reply, "Why, you are virtually denying that the substance of the muscle fiber is the real seat of muscular activity, thus implying a contradiction of the 'universally accepted principle that the 'potential chemical energy of the muscle substance is the primary source of muscular energy in all its manifestations^ ^^ for surely muscular energy *in all its manifestations' would include those elements of mus- cular acti^aty which are hereditarily distinctive of different kinds of animals." That the cytoplasm is at least the main source of the muscle substance furnishing this energy would not be ques- tioned, probably, by any histologist, but the definiteness of \aew held at the present time on this subject is worth re- calling and is indicated by such statements as the following: "The energy of contraction is the transformed surface- energy of the ultimate stiiictural elements or colloidal par- ticles (submicrons) composing the fibrils."-"^ Presumably there would be much difference of view among physiologists as to the validity of the chemico-physical part of LilUe's theory of muscular contraction ; but apparently there would be very little dissent from that part of his view which locates the processes, whatever their exact nature, in 64 The Unity of the Organism the muscle fibers. So it would be merely a matter of suf- ficient patience to go over all the tissue systems, epithelial, glandular, bony, nervous, and the rest, and point out nu- merous certain, and innumerable probable instances of dif- ferences for different taxonomic groups of animals, and to show that these hereditary differences are expressed pri- marily in the cytoplasm of the cells. Summary of Positive Informatioji about the Physical Basis of Heredity We have explored a vast region of fact and theory con- cerning propagation and development in organisms, for the purpose of ascertaining what is actually known about the organs and substances by which hereditary attributes are produced. Expressing the matter in terminology familiar to current discussion on heredity, we have been trying to find what is actually known about the physical basis of heredity. If clear-cut, unequivocal information of the kind sought is contained in all we have seen, it ought to be statable in a few simple sentences. What has been accomplished may be epitomized in two such sentences : First. Overwhelming observational evidence has been se- cured that the cytoplasm of cells participates directly in the formation of organic parts which hai^e hereditary at- tributes. Second. A great mass of evidence^ partly of observation and partly of legitimate inference from, the principles of organic integration, has been secured, that the chromosomes of the germ-cells in plants and animals which propagate by means of such cells, participate in the production of or- ganic parts having hereditary attributes. Any substance which plays such parts in development may be named a physical basis of heredity; and these two Evidence from Somatic Histogenesis 65 groups, or categories of knowledge must, it seems, serve as the foundation of all legitimate reasoning about sucli 'i)asis of heredity," or "inlieritance material," or "hereditarv fac- tors," or "bearers of hereditary qualities," or whatever ex- pression for the idea be employed. REFERENCE INDEX 1. Payne 190 2. Meves 81G 3. Meves 817 4. Meves 820 5. Meves 850 6. Meves 845 7. Cowdry ('14) 416 8. Cowdry ('16) 436 9. Lewis and Lewis 393 10. Locb ('06) 181 11. Conklin, ('15) 176 12. Ritter ('93) 13. Sedgwick 82 14. Minchin ('00) 107 15. Goodrich 2^1- 1 6. Cannon 13 17. Cannon 23 18. Goebel 367 19. Canipl)cll 51 20. Wieland 197 21. Jordan ('16) 493 22. Jordan ('16) fig. 7 496 23. Marceau 273 24. Marceau 280 25. Winterstein Ill 26. Luciani Ill, 85 27. Lillie, R. S. ('16) 255 Chapter XVI . THE INHERITANCE MATERIALS OF GERM-CELLS INITIATORS RATHER THAN DETERMINERS Antecedents of the Cytoplasmic and Nuclear Theories of Inheritance Material FOR the purpose of calling vividly to mind the character of the evidence on which the two propositions rest with which the last chapter ended, it will be profitable to cast a glance back on the course along which biology has come down to us, with a view to finding a shai'ply out- standing spot in the early growth of knowledge which led to each of them. On the botanical side such a spot in the knowledge of cytoplasm as hereditary substance, is the work of Schleiden on the microscopic structure of adult and developing plant tissues. The publication of his Ueher Phytogenesis, 1838, may be taken as the starting point of our knowledge of cellular transformation in the production of tissues. It should be remembered that the observers of that period had very hazy notions about the distinction between nucleus and cell-body, or cytoplasm. On the zoological side the publication by Ehrenberg, in 1836, of Die Infusionsthierchen als volkommene Organismen may, I think, be looked upon as the first milestone in the progress of knowledge of cytoplasmic transformation into tissue sub- stance. The ever-broadening stream of knowledge of the chromo- somes in relation to heredity is usually held to have orig- inated in the discovery forty years ago, by O. Hertwig, 66 Inheritance Materials of Germ-Cells 61 that tlie most essential fact in fertilization is tlie union of the nuclei of the male and female germ-cells. That cytoplasm is a physical basis of heredity is proved by a great body of direct observational knowledge. That the chromatin of chromosomes is a physical basis of heredity is proved by much observational knowledge when this knowl- edge is supplemented by reasoning involving the principles of biological comparison and correlation. These two masses of knowledge constitute, as already indicated, the founda- tion of all legitimate reasoning about inheritance material. Whether chromatin and cytoplasm are the only substances which participate in the formation of hereditary structures can not now be stated with certainty, though there are both observational and general grounds for believing that they are not. But into this question we need not enter in this discussion. Nor is it necessary for our purpose to inquire very particularly whether the conceptions of chromatin and cytoplasm really imply just two substances or two great classes of substances, though it is best to have in mind the undoubted fact that the latter alternative is the true one. Beyond a doubt "chromatin" and "cytoplasm" ought al- ways to be understood to mean "kinds of chromatin" and "kinds of cytoplasm." Function of Chromosomes in Heredity Acquired and Secondary The question which specially concerns us here is that of what the relation is between chromatin and cytoplasm in virtue of which they play the particular roles they are found to play in producing hereditary structures. PiM-haps tlie most important aspect of this general question is that wliich the theory of phyletic evolution naturally brings up: does the evidence in hand suggest any answer to the question whether chromatin or cytoplasm is the more primitive and 68 The Unity of the Organism fundamental as hercditarj^ substance? Surveying as we have the whole field of organic propagation, including the process in unicellular organisms as well as in multicellular, and sexless as well as sexual methods of reproduction, and taking the facts as they actually present themselves, it seems as though but one answer to this inquiry is possible: The substances included under the generic term cytoplasm are the more fundamental and primitive. The only possible way of escaping this conclusion is by excluding from the conception of heredity the vast majority of developmental phenomena presented by unicellular organ- isms and by monogenic propagation in multicellular organ- isms. As our examination of these provinces revealed, such exclusion is exactly what the chromatin dogma of heredity has undertaken, implicitly or explicitly, to fix upon biology. The utter unwarrantableness of this undertaking was made sufficiently obvious, we may assume, by the examination ; so we need spend no time on that now. All that is necessary is to remind ourselves vividly of the main positive outcome of the examination : Heredity is a universal phenomenon of the living world. It is coextensive with organic propagation and development, while "carrying heredity" by chromo- somes is, according to the evidence, very far from a uni- versal phenomenon. It is a long way from being coex- tensive with organic propagation and development. We may, consequently, proceed in our quest of a more rational, more consistent, more satisfactory conception of the purely operative side of producing hereditary structures. Pur- suing the quest, we remind ourselves of having found that only the most meager observational evidence is afforded by the protophyta and protozoa, and by monogenic metaphyta and metazoa, that chromatin is hereditary substance, while these organisms afford an ovei-whelming mass of such evi- dence that cytoplasm is hereditary substance. But if in the lower, more primitive moiety of the organic Tnherifance Mafer'iah of Gcrm-CcUs 69 realm, clironiatln is a ])lijsic'al basis of litTcdity to only a limited extent and in a partial way but has this office widely and positively fixed in the higher moiety, the moiety, tliat is, in which bisexual propagation is I'ully establislied, uliat other conclusion can be drawn consistently Avith the modes of reasoning universally sanctioned by evolutionists, than that the function of "carrying hereditary qualities" by the chromosomes in higher organisms is a secondary or ac- quired, or better a delegated or assigned function? Hered- ity is far older, phylogenetically, and far broader tax- onomically than is the chromatin mechanism by which it now in part manifests itself. Under this interpretation the acquisition by chromosomes of the function of carrying heredity would belong to the same evolutional type as for example the acquisition by certain cells of the function of muscular contraction, or by certain other cells of con- ducting nervous stimuli. The advantage and satisfaction of a conception of the role of chromosomes in heredity which ranges them naturally and easily with all other or- gans and tissues of the plant and animal body will be quickly seen by every one to whom the seemingly endless chance of discovering new interrelationships and consis- tencies jn living nature is one of the most rewarding things about biological investigation. While we are duly impressed with the importance of per- ceiving that chromosomes fall into the great class of otlier organs and tissues when considered from the standpoint of phyletic differentiation of structure and function, we should not fail to notice that within the class they hold on a number of counts a very distinct place. Probably the most distinctive of these counts, at any rate the one most important for this discussion, is the fact that while the vast majority of tissues, taking the term in its usual meaning, stand at or near the termination of the ontogenic series — are, in other words, the final stage in the series — the chro- 70 The Unity of the Organism mosomes in their function as bearers of heredity stand at the beginning. They represent the initial stage in the series. Furthermore, their function in this respect is unique as contrasted with the function of other tissues, in that while other tissues liave, typically, each a single function wliich they perform immediately, the chromatin of a given germ- cell has a great complex of functions, namely, that of ini- tiating the development through which all the attributes of the individual during its whole life-career are developed. In a word, chromosomes of germ-cells are not determiners or carriers of determiners ; they are initiators or carriers of initiators. They may, then, be called bearers, or carriers of heredity in a very literal sense, namely in the sense that they are made use of by one individual, the parent, to carry across or transfer from itself to another individual, the child, the hereditary attributes of tlie species in a latent or potential state. By virtue of their being thus used, they are members of a developmental series, in which series their place is at the beginning and not at the end, the nature of the series depending on the phylogenic history of the par- ticular organism to which the particular chromosomes be- long. The Two- fold Character of the Problem of Hereditary Substance At this point it becomes a matter of the greatest im- portance for theories about hereditary substance to dis- tinguish between the problem of the operation of such sub- stance in the developing individual, and that of how sucli substance ever came to* be hereditary substance; stated otherwise, between the problems of how any substance par- ticipates either directly or as an agent in the building up of a structure having hereditary attributes, and that of how the substance itself became impressed with the attributes, in Inheritance Materials of Germ-Cells 71 a latent state, of tlie progenitors of the developing in- dividual. Investigation of the first of these j)roblems is to a large extent a matter of observation, as we have seen in the pre- ceding pages. The sub-science of histogenesis consists largely in tracing out the processes by which completed tissues arise by the transformation of less differentiated or undifferentiated cells. And when such newly arisen tissues and structures are proved to be hereditary by such evi- dence as we have called attention to, then the study of histogenesis comes to be so far a study of hereditary sub- stance. When, however, we turn to the other problem, that of how hereditary substance comes to be such, we are in a different, a much more difficult case, for so far science has succeeded in getting almost no obsei'vational hold upon it; and despite the vast discussion it has received the darkness that envelops it is hardly an iota less black than it was the day of its original formulation. But stygian as the darkness is, here, especially as to details, we yet are able to see, probably, the quarter from which light will come if ever it does come. That quarter is the physical-chemistry con- ception of the organism as a system of phases the whole of which, as a species entity, is essential to its equilibrated activities. This nature of the organism, together with some- thing akin to its internal secretory and enzymic productiv- ity, enables it, we may conjecture, by some means now wholly unknown, to reflect its totality of transferable at- tributes upon the germinal cells and to transform thrni into a latent state. Ungrudging acknowledgment of the complete- ness of our ignorance of how any part of a cell or any other portion of an organism becomes endowed witli the capacity to develop or causally to affect the development of an organism similar to that from which it came, should he an important item in the preparation to accept any and all indubitable 72 The Unity of the Organism facts connected with heredity, even though no causal ex- planation of them is forthcoming. The childlikeness, as Conklin well characterized it, of the belief that chromosomes are a simple and complete ex- planation of inlieritance would not be so bad in itself. If it stopped there, as genuine childHkeness would, no posi- tive harm could be done. It is the making of this belief the starting point of a grand speculation which blinds the eyes and closes the mind to a vast number of facts and legitimate inferences about heredity, that plays havoc with thinking on genetics. It would be a great gain if gen- etic theory would recognize wholeheartedly that all or^ ganic development, as contrasted with mere enlargement, consists more fundamentally and obviously in transforma- tion of substances than it does in unchanged continuity of substances. For under such recognition the futility of attempting to explain the transfonnation of one lot of substance by referring it to another lot which does not transform, or in other words to explain development by something that does not itself develop, would be manifest. That the chromosome theory of heredity in reality deep- ens rather than illumines the darkness which surrounds the problem is seen when one reflects that not only does it throw no light on the question of how the chromosomes come to be bearers of heredity, but that it creates the new and equally difficult question of how the chromosomes (which ac- cording to the theory maintain unchanged their individuality not only from generation to generation but throughout each ontogeny) are yet able to be causally operative in the cell- bodies undergoing the transformations which they actually do undergo in the developing organism. That the germ- plasm-chromosome theory of heredity could have led its devotees to sidestep the details of ontogeny, especially those of histogenesis, to the extent which our review has shown it to have done, would be unbelievable but for what is Inheritance Materials of Germ-CeUs 73 actually before us in tlie recent history of hioloirv. Aiewin^tp heredity as bein^- dcfinitiyely a kind of organic transformation — transformation, that is, in accorchmce witli a pre-existing or ancestral ])attern more than it. is a kind of continuity — it becomes obyious that even were the dem- onstration to become complete that the chromosomes arc the only ])ortions of the germ-cells * essential to fertiliza- tion, they still would not be proved bearers of heredity in such sense as the germ-plasm theory holds them to be. They would not because the problem of the transformations which constitute ontogeny would still be initouched. The theory would be established only when the demonstration should be produced that the chromosomes cause immedi- ately all the particular ontogenic transformations known to be hereditary. All that would be proved about heredity by demonstration that the chromosomes alone participate in fertilization would be that the chromosomes alone con- stitute the first ontogenic stage of the hereditary parts of the particular organism to which the fertilized Qgg gives rise. The Frohahility That Inheritance Material Becomes Siicli In Each Ontogeny But because thus far failure has attended all efforts to get knowledge of how hereditary substance is produced, are we obliged to own that we know nothing at all, even inferentially, about its production? And is tlie search for such knowledge to be given up as hopeless? ^fy answer is an energetic negative to both these (juestions. In tlie first ])lace, there is much evidence to support the hypothesis, very general to be sure but yet by no means devoid of use- fulness, that hereditary substance becomes such in some * The utter uinvarrantableiiess of the eonmion assumption that as regards the male germ-eell sueh a demonstration is "praetieally eom- plete" will be noticed presently. 74 The Unity of the Organism way through being subject to the metabolic processes com- mon to the whole organism. Undoubtedly the germ-plasm dogma itself has tended strongly to divert attention from this aspect of the problem of germinal material — indeed, has tended to minimize the importance of the metabolism of such material even if it has not tended to deny that the material is subject to this process. So important is it from the organismal standpoint to conceive the material basis of heredity as part and parcel of the organism generally, especially as regards the basal growth and sustentative processes, that we must examine in some fullness the evidence favorable to such a conception. In its most brazenly evidence-ignoring form, the gerai-plasm dogma asserts that the female parent does not really pro- duce the eggs or the male parent the sperm, as they seem to, but that these are produced by previous germs ad in- finitum. There are, to be sure, quite a number of observ- able facts, as those of the early formation of germ-cells in several animals, that can be forced into a seeming sup- port of such a conception. But the familiar and all but uni- versal fact that multicellular organisms, plants and animals alike, are sexually immature for a shorter or longer part of their lives, the very essence of the immaturity being the un- developed state of the reproductive system, would be a sufficient refutation of the view for any mind not made impervious to facts by long and faithful sophistication. Germ-Cells Subject to Metabolism Like All Other Cells The biological commonplace that all germ-cells, like all other cells, undergo a process of growing and maturing before they can perform their distinctive office, and that this process depends upon the retention of the germs by the parent organism, ought, as already indicated, to be a suf- ficient antidote againjst the germinal continuity fallacy, Inheritance Materials of Germ-CeUs 75 even tliough nothing" were known as to exactly what goes on in the germ while it is growing and ripening. Ihit we are by no means without positive knowledge uiuUr this head. In fact the last few cell divisions innnediately pre- ceding the ripening of both ova and spermatozoa, and the ripening processes themselves, have received searching ex- amination during tlie last few decades, with the result that hardly any cytological phenomena are better known than are the profound morphological changes which accompany these j)rocesses. That these changes are particularly mani- fest in the chromosomes, the assumed seat of the determiners of heredity, is one of the very things that has aroused so much interest in the processes. Nor are we wholly unin- formed about the chemical changes taking place in the growing germ-cells. Unfortunately knowledge in this field has hardly passed the stage of early infancy, but at least enough is known to warrant the assertion that the young germ-cells are subject, as are all the other cells, to the general metabolism of the organism. Chemical Changes in Germ-Cells During Parcnfs Ontogcnjj About the most striking information wc liave in this field is what has come from such investigations as those on the chemical changes which occur in the sex glands and other body parts during reproduction in some fishes.* Mic- scher's work was ground-breaking in this domain for it was the first to show that the "sexual organs in the salmon develop at the expense of the muscular system, and tliat the salmine deposited in the testis during the breeding season must be derived from the proteins of the nuiscle, since the * Notable among these studies are: Histocliemische und physiolotjischr Arbeiten, gesammelt und herausf/ff/ehev von seinen Freiindin, by Mio- cher; and Changes in the Chemical Composition of the Ilerrina dtirina the Reproduction Period, by Milroy. Biochemical Journ., v. iii, 1908, p. 366. 76 The Unity of the Organism fish does not take any food during the period." ^ The work of Riddle and his collaborators is producing evidence to the same effect. Such researches do not, to be sure, prove that the chem- ico-physiological changes extend to the chromosomes of the germ-cells, much less to the imaginary determiners of hered- ity in the chromosomes. But viewing the results in the light of the well-grounded general belief that the mdst fundamental test of living substance is metabolic change, it is seen that any hypothesis which assumes the existence in the germ-cells of something virtually not subject to the general metabolism of the cells, assumes at the same time the burden of furnishing objective evidence that such a something does exist. As a matter of fact the prime offense of the gerai-plasm- determiner hypothesis is that its very essence places it beyond the reach of scientific observation. Such truth as it may contain cannot be made really effective because it can not be proved, and such error as it may contain can not be robbed of its power for evil because it cannot be dis- proved. In a word, the hypothesis is one that belongs to the realm of dialectics primarily, and has no just claim to a place in inductive science. The Possibility of Changing Sex By Influences on the Germ But perhaps the most conclusive evidence of the funda- mental dependence of true germinal material upon the or- ganism, should somewhat fuller verification of the obser- vations be obtained, are results like those reached by Whit- man, King, Whitney, Riddle, and by R. Hertwig and his students, according to which sex may be reversed in several animal species by various conditions extraneous to the germ itself, acting on the germ-cells from which the animal is to develop. The instance of this usually regarded as best established is afforded by certain species of frogs and toads. Inheritance Materials of (icrvi-Cclls 77 The widely known result reached hy Hertwig and vurlHed and extended by Kuschakewltsch ex})re.ssed in a single sen- tence, is that the number of males and of females ])ro(luced by the eggs of a given female depends upon whether the eggs are fertilized when newly rij)e or when over-ri})e, a great ])redominance of males coming from the latter class. In a tabulation of the results of four sets of experiments \)\ Hertwig " almost every case shows the number of males increased when the time elapsing })etween deposition of the eggs and fertilization was increased, the highest percentage of males in any one lot being 759, fertilization in this in- stance having been twenty-two hours after the fertilization of the last preceding lot. In a species of toad, Bufo lentigijwsus, results have been obtained just the reverse of those on the frog, that is, the proportional number of females has been experimentally increased. This was accomplished by fertilizing the eggs in water made slightly alkaline. Since frog eggs are known to absorb water when they remain long in it, as in the case of those which gave rise to a preponderance of males in the Hertwig method of experimenting; and since alkaline solutions extract water from eggs, and likewise cause them to produce a preponderance of females, Miss King drew the obvious conclusion that the quantity of water contained in eggs of these animals may be a factor in determining the sex of the animals developed from the eggs. Although Miss King recognizes that her experiments do not furnish final proof of the conclusion she draws, she believes, rightly it would seem, that they weigh heavily in tliat direction. "As they stand," she writes, "the results strongly suggest that sex in Bufo is determined at or near the time of fer- tilization, and that external factors acting during this ])o- riod may influence the sex-determining mechanism in such a way as to cause it to produce one sex or the other. The results also seem to indicate that in Ilufo sex is determinwl in 78 The Unity of the Organism the ^ggi and that it may depend in some way on the rela- tive amount of water in the ^gg at the time of fertiliza- tion." 3 Riddle, perhaps the most outspoken opponent of sex pre- destination now writing, strongly espouses the hypothesis that the sex to which a particular Qgg will give rise is de- pendent partly on the quantity of water which that Qgg contains. But whether water is a factor in determining sex or not, the evidence presented by Riddle, coming partly from researches by C. O. Whitman and partly from his own, constitutes, when taken with the evidence to the same effect presented by other investigators, almost if not quite com- plete proof that sex is not the hard-and-fast thing which most present-day genetic speculation would make it. Furthermore the evidence produced by these two inves- tigators seems to connect the decision as to which sex a particular ^gg shall give rise, with some condition of the parents. It is well known to all zoologists, in the United States at least, that at the time of his death Professor Whit- man had accumulated a vast store of data on the habits, particularl}'^ the breeding habits, of pigeons. To Doctor Riddle, who had worked with Whitman considerably, fell the task of carrying on to some extent Whitman's experi- ments and of preparing for publication the results which Whitman left in the rough. The following quotation from Riddle's paper referred to above, summarizes Whitman's results that are especially important for us now: "Whit- man found that if certain very distantly related pigeons [i.e., two individuals from different families] are mated that only male offspring resulted. If the matings were made of individuals not quite so distantly related — different genera usually — and if to this situation be added the ele- ment of overwork at reproduction [i.e., the birds not being permitted to nest their own eggs, but forced to keep laying eggs in rapid succession] then the first several pairs of Inheritance Materials of Germ-Cells 79 eggs produced in the spring will produce all or nearly all males. The last several pairs of eggs laid in autumn will produce all, or nearly all, females. At the transition period in the summer he found that some pairs, or clutches, of eggs produced both a male and a female. In these cases it was usually the first Qgg that produced the male; and the sec- ond e^gg — laid forty hours after the first — that gave rise to a female." ^ Into Riddle's interesting discussion of Whitman's results and his own chemical studies on the eggs of pigeons and hens we need not go. Suffice it to say that it seems to me Riddle is justified by the evidence now in our possession, in his contention that "sex rests upon a quantitative and reversible basis" and that in this sense it has been controlled by conditions extraneous to the genn-cells themselves. This does not imply, as I understand, that such control would necessarily be practicable of even possible in all organisms, nor does it preclude the possibility that in some species there may be dimorphic or partially dimorphic spermatozoa or ova as regards sex production. Neither does it preclude the possibility that in some cases where a preponderance of one sex has been observed, this is due to selective mor- tality or some process other than the actual shifting of the sex tendency in the particular eggs. These several concordant bodies of testimony must, it would appear, open the eyes of biologists sooner or later to the ludicrousness of a theory that would make the parent organism hardly more than a combined culture medium and incubating oven for its germ-cells. The Determiner Conception Contrary to Ordinarif Chem- ical Principles If, on the basis of such facts as we have, we try to come still closer to the questions of how the assimilative and morphogenic processes of the organism occur, whether in 80 The Unity of the Organism the production of hereditary substance or in the transform- ation of such substance into actual hereditary structures and activities, we find ourselves hedged about on every side by partial knowledge, by dubious knowledge, and by com- plete ignorance on many fundamental points. However, chemical considerations seem to point the way to future discovery. In the first place, it seems necessary to recognize that the whole germ-plasm conception as orig- inally promulgated, with its interminable system of "bear- ers" and consummators, was contrary to what is well known about chemical processes generally. Thus the continuity presented by a complex chemical operation does not consist in an unchanged series of individual entities of some sort, such as determinants and determiners are, or originally were conceived to be, but rather in a regular succession of transformations. For example, when chromic hydroxide, which is grayish-green, is dissolved in acid, a green solu- tion results, which turns to greenish violet or pure violet if allowed to stand a long time. Exactly what the chemical changes are that correspond to these color changes I do not know, and probably the information which chemists have on the subject is not exhaustive. At any rate modem chemistry conceives the phenomenon to consist in a succes- sion of reactions and transformations, the various colors and shades being attributes of the compounds that exist in the various stages along the way, and not as due to in- dividual bodies carried by the preceding stages for the express and exclusive purpose of producing the particular colors that are observed, as would be implied in such a metaphysical scheme as was the germ-plasm theory elab- orated by Weismann. Enzymic chemical action presents perhaps a still better starting point for imagining what the fundamental hered- itary processes may be than does ordinary chemical activity like that just instanced. The essence of this kind of activ- Inheritance Materials of Germ-Cells 81 ity is, as everybody knows, that in some way enzymes cause or at least facilitate transformation in other substances. Thus the attribute of solubility of tlic sugar Into whicli starch is transformed, through tlie action of tlie saHvarv enzyme ptyalin, is not held to be due to a determiner f(}r solubility carried by the ptyalin and passed on into the sugar, but rather it is recognized tliat sohibiHty is one of the attributes possessed by the kind of sugar into ^vhich starch is converted by the ptyalin. The solubility is thought of rather as an attribute of the sugar and not as something once latent in the ptyalin which produced the sugar. A few details of the action of the enzj^me in this case illustrate the point still better. Maltose, which is the chief if not the only sugar resulting from the action of ptyalin, is not reached by a single bound, as one might say, but through a series of bodies known as dextrins, at least three of wliich have been recognized. These are amylo- erythro- and achroo-dextrin, named from the color they display Avhen treated with iodine, the first mentioned turning blue, tlie second red, and the third remaining colorless. What mod- ern chemist would think of explaining the blue of the amylo- dextrin by a "determiner" for that color in the ptyalin or even in the starch, the red of the erythrodextrin by an- other determiner for red, and so on.? That is the sort of explaining chemists of a century ago did, but they have long since learned not merely the futility but the scientific evil of such explanation. If it were germane to our ])resent task we might go on and show that the gene conception in modern giMietics is really a revival in biology to-day of the geri-e conception which passed muster in chemistry a hundred years ago, when oxygen and hydro(7r7J were named. Such an exposi- tion would be appropriate to a history of scientific theory or to a treatise on the theory of natural knowledge, hut hardly to the present work. 82 The Unify of the Organism Endorsement of E. B. Wilson's Proposal to Drop "De- termvner^' From the V ocahulary of Genetics In his Croonian Lecture having the title The Bearing of Cytological Research on Heredity, E. B. Wilson said, "In the meantime it would be well to drop the term 'determiner' or 'determining factor' from the vocabulary of both cytol- ogy and genetics." ^ If the facts and arguments set forth in the preceding pages are valid, they constitute a demon- stration that not only would it "be well to drop the term 'determiner,' " but that it must be dropped, at least in its present application, before thought and investigation on the mechanism of heredity can be free and in very deed truth- seeking. "What we reall}'^ mean to say," Wilson continues, "is 'differential' or 'differential factor,' for it has become entirely clear that every so-called unit character is pro- duced by the cooperation of a multitude of deteiTnining causes." So far as these statements go they are in strict accord with the organismal standpoint maintained in this volume, and we may also say, with the physical-chemistry standpoint. Where attributes of adult organisms have been so defin- itely correlated with particular chromosomes and possibly parts of chromosomes of the germ-cells as seems to be the case in the fruit flies, such chromosomes are unquestionably differential, and since they stand at the very beginning of a long and complex transforming and developing series, they may very properly be called differential factors even though they do not themselves participate substantively in the transformation. The general similarity of their mode of action to that of enzymes is certainly considerable : a minute quantity of the substance is capable of inducing or facili- tating the transformation of a large amount of other sub- stance in a perfectly definite manner, and the inducing agent is not itself consumed. Inheritance Materials of Germ-Cells 83 Advantages of Conceiving Germ-Cell Chromosomes as Initia- tors in Hereditary/ Development This chemical way of viewing chromatin and chromosomes sanctions the idea that these are to be regarded as initiators of developmental processes which lead to hereditary attri- butes, rather than determiners of those attributes. If one wants to know in what way this conception would liave an advantage over the determiner conception as a working hypothesis, my reply is that the advantage is two-fold. First, it would surely correct the tendency of genetic re- search under the guidance of the determiner hypothesis, to restrict its attention to attributes of adults at one end of the ontogenic series and to the chromosomes of the germ- cells at the other end, and to ignore or touch only in the lightest way all the intervening parts of the series. This correction would result because the new standpoint would bring the whole series of continuities and transformations alike into proper perspective, revealing thus that the mem- bers of the series intervening between germ and adult must be investigated in exactly the same way and with the same objects in view as the end members, if complete understand- ing of the hereditary process be the goal of research. It could not then happen that the egg-cell would be repre- sented, as it now so commonly is, as a relatively large sac containing nothing significant for heredity except the rela- tively small chromosomes. Nor could nearly the whole mass of ontogenic phenomena, especially those of histo- genesis, be treated so lightly in speculation and so largely neglected in investigation as they have })een under the domination of the determiner theory. The second advantage in the initiator conception is tliat since it would recognize the "differential factor" of tin- chromosomes to be in reality due to the fact that the wliole ontogenic series to which the chromosomes belong is dilfLr- 84 The Unity of the Organism ential, that is, that it pertains to a particular species or kind of organism, it would put an end to the notion by which recent genetic science has been so largely dominated, that the problem of how the series came to be thus specific or differential may be solved by speculation, and it would incite geneticists to efforts to solve the problem by obser- vation aided by experiment. It is impossible to refute the charge that genetics is to-day more interested in an elab- orate system of conceptions — of speculation, in other words — than it is in obsei'ved or possibly observable phenomena. We cannot keep too constantly before our minds the fact of our almost complete ignorance of how any substance becomes hereditary substance whether through the "inheri- tance of acquired characters" or in any other way. Hence mere speculation on the subject after the manner of the pan- gens idea is much worse than nothing if permitted to run into a bewildering and enslaving system like that of the germ- plasm theory as it came from Weismann's mind. Neverthe- less it is quite germane to the present discussion to point out that whatever might be the nature of the chemical ac- tion, whether enzymic or some other, through which the series of ontogenic transformations should be accomplished, the character and subtlety of these processes seem to make them, more than any others we know, competent with some modification to serve as the go-between for impressing the germinar material with the latent attributes of the species. Inconclusiveness of the Cytological Evidence Usually Ap- pealed to in Support of the Chromosome Theory And this leads to the concluding statements of this dis- cussion. The three categories of cytological fact which have been weightiest in the formation and maintenance of the chromosome theory of heredity are the individuality and continuity, chiefly numerical, of the chromosomes from par- Inheritance Materials of Germ-Cells 85 cnt to offspring; the apparent equality (it should never be forgotten that the dogma of equality does not rest on rigor- ous quantitative investigation) of the chromosomes in the male and female germ-cells; and the assumption that in tlie male germ-cells the chromosomes alone are concerned in fertilization. Kven if these groups of assumed fact were established with absolute certainty they would fall far short of being direct and final proof that chromatin is tlie only hereditary substance. That this is true must be ap})arent to all well-informed, carefully thinking biologists. The most important grounds for this inconclusiveness are in- volved in the facts and arguments set forth in the preced- ing pages, but they may be summarized here, and in addi- tion two other grounds may be pointed out. First and foremost, in my opinion, is the general trutli that chromosomes or even chromatic substance can not pos- sibly be recognized as the sole bearers of hereditary sub- stance, because the evidence is enormous in quantity and direct and indisputable in quality that other substances })ar- ticipate actively in the production of hereditary attributes. There is no way of escaping this conclusion except by nar- rowing the definition of heredity for the very purpose of bringing it within the scope of the chromosome theory of hereditary substance. The scope and fundamentalit}^ of this aspect of the problem is sufficiently dwelt upon, we may hope, in what has gone before. The two additional grounds for skepticism as to the con- clusiveness of the cytological evidence will now be pointed out. First, as to the evidence from the individuality and continuity of the chromosomes. All tliat any carrful thinker claims or can claim for this evidence is tliat the individuality and continuity of chromosomes as observed are what might be expected if they were the germinal i\v- pository of the organism's hereditary attributes. Antl the question is constantly and naturally asked, what other 86 The Unity of the Organism meaning can the whole remarkable series of phenomena of maturation and fertilization have than that attributed to them by the chromosome theory? My rejoinder to this argument may begin with a reply to the question. As long as knowledge of the chemistry and physiology of cells — germ-cells with the rest — is as fragmentary and inconclusive as it now is, certainty as to the meaning of the phenomena mentioned is out of tlie question. However, it would seem quite probable that they are concerned primarily with the nutritive and assimilative processes of the cell and only derivatively with heredity. Furthermore, the question asked may well be paired off with another of' similar character, namely, what is the meaning of the almost if not quite com- plete breaking up and disappearance of the chromosomes in the so-called resting stages of the immature germ-cells, this being accompanied by the dissolution of the nuclear mem- brane so as to allow the freest possible commingling of the whole nuclear contents with the cytoplasm of the cell.^^ Have we not at least as much factual right to suppose that during this mixing of substances the chromatin, and so later the chromosomes, are influenced by the cytoplasm, as that the reverse influence takes place .'^ Is it not entirely possible that this process is one of the very means or occasions of impressing the chromosomes with the attributes of the or- ganism which, as we have seen, apparently must take place whether acquired charactei's are ever inherited or not.^ And now as to the argument from the assumed exclusive participation of the chromosomes of the male germ-cell in fertilization. First of all, it can not be admitted for a moment that the chromosomes are proved to be as ex- clusively the fertilizing agents as they are generally as- sumed to be. Even in such extreme cases of seeming ex- clusiveness of chromosomal participation as that claimed by Strasburger for the pollen cells of some plants, neither Strasburger nor any one else has claimed, so far as I know, Inheritance Materials of Germ-Cells 87 that all other male substances tlian chromatin arc excluded as rigidly as would be required by experiments in a chemical hiboratory designed to ascertain tlie action of a particular chemical element or substance in its purity. It is certain, for example, that in almost if not (juite all male genninal elements in animals, a thin outer layer from the cytoplasmic part of the spennatid is present on the head of the sperma- tozoon. Furthermore, it is well known that at least the "intermediate piece" of the sperm tail, which is not usually regarded as chromosomal in origin, remains in the Qgg at fertilization. Nor is there any good ground for su})posing that the non-chromatinic portions of the nucleus are ab- solutely excluded. The almost certain presence in the cg^g at fertilization of at least these male substances other than chromatin can by no means be regarded as insignificant for heredity, especially if the initiator conception of germinal material is held. It seems to follow of necessity that if the fertilizing substances, whatever their source, be conceived to act in an organic system of the physical chemistry sort after the manner of enzymes, no such quantitative relation subsists between these fertilizing substances and the prod- ucts of organic growth as the chromosome theory implies ; nor can their action be so narrowly localized in the (^gg. Their action would be conceived to involve the entire ovum ah initio, and not the chromosomes alone. Summing Up of the Findings Against the Chromosome Theory The general result of our critique is that the whole at- tempt to interpret the physical basis of heredity in accord- ance with elementalist conceptions has failed and must con- tinue to fail, so far as its main aim is conccrnrd. We are led to see that the germ-plasm dogma, no matter how often or how completely it changes its nomenclatural habiliments, 88 The Unity of the Organism as in the shifting from deteYmma7its to determiners, or from determiners to ge7is, or from gens to factors, involves a rejection of the conception that the germinal elements of organisms, after being discharged are literally detached parts of those organisms. This conception was well on the road to incorporation into the great body of established biological truth when it was headed ofF by Weismann's diametrically opposed hypothesis of germinal isolation. I would insist that the defense of the organismal concep- tion in this volume is really a carrying out of such a con- ception of the organism and its germinal products as is implied by the old view that the germ is a part of the parent organism. It would hardly be possible to express more sat- isfactorily in a single sentence the most inclusive theo- rem, as it might be called, the demonstration of which is the aim of the part of this volume devoted to the means by which organisms propagate their kind, than the following from E. B. Wilson: "To the modern student the germ is, in Huxley's words, simply a detached living portion of the substance of a preexisting living body carrying with it a definite structural organization characteristic of the species." ^ Coupling this statement by Wilson with another from one of his latest writings,^ to the effect that we ought to drop the term determiner because in reality what it means is differential, I call attention to the fact that the "dif- ferential factor" of the later statement and the "definite structural organization characteristic of the species" of the earlier statement are in essence one and the same. The only difference is that in the earlier statement it is the whole germ-cell that is recognized to be a detached part of the organism, while the later statement can be brought down to the chromosomes because of the greater refinement of knowledge attained since the earlier one was made. The point I wish to make stand forth with the greatest possible Inheritance Materials of Germ-Cells 89 boldness is tliat the germ-cell chroinosomcs may properly enough be said to be differential, if only one never loses sight of the fact that they are differential in no other sense than are any other particles or substances of the germ- cells or any other cells which participate in the production of species-attributes. Brief Reference to the Untoxcanl Implications of the Germ- plasm Conception of Heredity The somewhat laborious task of exhibiting the difference between conceiving the phj^sical basis of heredity from the elementalist and from the organismalist standpoints may well be brought to a close by calling attention to the impli- cation of the two conceptions as applied to heredity in man himself. Looked at from this direction the germ-plasm dogma is seen to be chargable with the grave offence of having added its weight to a conception of human life, the overcoming of which has been consciously or unconsciously man's aim throughout the whole vast drama of his hard, slow progress from lower to liigher levels of civilization — the conception that his life is the result of forces against which his aspirations and efforts are impotent. As ap- plied to man this form of fatalism is no less sure and no less dire in its tendencies than have been any of the innumerable theistic forms of fatalism that have prevailed through the centuries. It is almost certain that the ardor with which Eugenics has been espoused by several biologists is due in considerable measure to the fact that they have felt more or less definitely this sinister im])lication of the theory, and have turned to Eugenics as the only weapon against its evil forebodings. The germ-plasmic eugenist virtually says, "Yes, indeed is man a reasoning, willing, as jn' ring animal, but all his activities In these ways are futile so far as the race as a whole is concerned, except as they are 90 The Unity of the Organism brought to bear, extrinsically and operatively rather than organically, on the Germ-Plasm." This form of the Eu- genic idea corresponds in spirit to the propitiative offerings of primitive religion. It aims to mollify by human agency powers that act upon men's Hves, but which are in them- selves largely extraneous, largely evil, and wholly irre- sponsible. What eugenists of this school have failed to see, evidently, is that even were unit-factors as differentiate from one another in heredity as the extremest Mendelist conceives them to be, and that even were the germ-plasm improved up to the level of his highest hopes, his results in terms of ac- tual human lives and social conditions would be distressingly meager. They would be so, because whether unit-factors exist independently in heredity or not, they certainly do not exist thus independently in development and function. In these ways they interact upon one another in the most vital manner, as physiology, especially of the internal se- cretions and the nervous system, and as physiological and social psychology are rapidly and conclusively demon- strating. We thus end our examination of the means by which or- ganisms produce others of their kind with the conclusion that the material through which reproduction is accom- phshed is in the most vital way part and parcel of the organism, that is, that the germ-cells are somehow stamped through and through, potentially, with the characteristics of the kind, or race, or species to which the producing or- ganism belongs. And with this we are ready to pass to the examination of those integrative phenomena of the organ- ism generally, one manifestation of which is this very nature of the germ-cells. REFERENCE INDEX 1. Marshall 292 4. Riddle 10 2. Hertwig, R. ('12) 75 5. Wilson, E. B. ('14) 351 3. King 232 6. Wilson, E. B. ('00) 7 PART II THE CONSTRUCTIVE SIDE OF THE ORGANISMAL CONCEPTION Chapter XV II GROWTH INTEGRATION The Field to he Covered hy the Constructive Discussion ACCEPTING the inevitable destructive result of our cri- tique of the clemcntalist standpoint, that the attempt to interpret living beings in the terms of their constituent parts alone always leads to partial failure and disappoint- ment, or to the worse result of illusionment as to the trust- worthiness of the explanations proposed ; and accepting the constructive result that everything in the critical study tends to show that no part of any organism can be rightly inter- preted except as part of an individual organism, this indi- vidual being in turn interpreted as a member of a taxonomic group, it is revealed that we are only on the tlireshold of tlie positive, the constructive side of our general enterprise. Even though the conclusion be unescapable that the living organ- ism someliow acts causally on its parts, the problem still remains as to the modus operandi of tliat acting. The "some- how" which came to us as an incident of our critical study has yet to be inquired into. Stated more specifically the task now Inforc us is Hiat of examining closely and systematically the interdependences among the parts of the individual organism. Although these interdependences are among the most obvious and general of all organic phenomena such an examination of them biol- ogy has not yet made systematically. Indeed — and here is one of the most vital things for us to see — a cardinal charge against the elementalist standpoint is that in its very nature 93 94 The Unity of the Organism it not only does not encourage, it actually stands against such examination. Its opposition to comprehensiveness and systematization is profound and essential. Our examination will begin with a single brief, two-parted definition : The structural and functional interdependence found to exist among the parts of an organism we call hio- integratedness; and the process of moving on from grade to grade of interdependence among the differentiating parts which constitutes ontogenesis in the individual we call hio- integration. Four Types of Bio-integration to Be Treated In the present state of knowledge and for the discussion now before us four types or kinds of bio-integratedness and bio-integration may be recognized as pertaining to the in- dividual organism : 1. Growth integration, most obvious in graded meristic series, but also expressed in the "axial gradients" of Child. 2. Chemico- functional integration, known so far chiefly in connection with internal secretions. 3. Neural integration, comprising the interdependences among the parts of the nervous system, and the involvement with this of the muscular, glandular and other organs. 4. Psychic integration, very closely connected with neural integration, but approached from the side of the totality of activities of living beings rather than from the side of nerve- organ activity, and so taking cognizance of a vast number of phenomena not yet definitely cor relat able with neural phenomena. The full presentation of facts and arguments under these four heads would reach far beyond the limits set for the present work. We are, consequently, obliged to restrict ourselves to a small portion of the best established and most compelling evidence under each head. Growth Integration 95 Graded Repetitive Series as Integrative PJienojrwna This, perhaps the simplest form of integrational phenom- ena known to biology, is seen almost everywhere, but shows itself most typically and strikingly in plants and in many lower animals. Reference is made to the gradation in the repetitive or meristic parts appearing in so many organisms. The most obvious criterion of sucli gradation is the rela- tive size of the parts, but, as we shall see later, there is con- siderable reason for supposing the gradation is not re- stricted to size. The few examples to which space can be given are selected to represent as wide a range as possible of the phenomena under consideration. Illustrations from Ani/mals \ The lancelets, fish-like animals of the genus Amphioxiis, may be noticed first (Figure 55). It will be obsei-^ed that "^^ <*»*a ^- FIGURE 55 — SIDE VIEW Or AMPIIIOXUS ( AFTER PARKKR 4c IIASWELl). Iicll., notocliord. cir., cirri, or.hd., oral hood, myoni., myomeres, dors.fr., dorsal fin rays, cd.f., caudal fin. gon., gonads the creature tapers oft* toward botli ends and that the series of metameres, myom, usually called myomeres because they compose the main body-musculature, diminish not only in dorso-ventral measurement from near the middle each way, but are also thickest in the mid-region and become thinner as they progress toward each end. Something of this size scheme of body-parts is very com- 96 The Unity of the Organism mon in the animal kingdom. Figure 5Q, a photograph of the skeleton of a python (see frontispiece), shows in a gen- eral way the size-relations of metameric skeletal parts in a higher vertebrate. Something of the extent to which the proportionality of parts of the individual metameres is car- ried out in this skeleton is shown by tabulating a series of measurements of the parts : Position of vertebra L.V. T.V. T. ex.zyg. H.D.S. W.D.S. L.R. 5 6 mm 5 mm. 11 mm. 15 mm. 4 mm. 25 mm. 50 11 16 23 11 8 48 100 13 17.0 28.5 9 7 79 150 13 16.5 26.5 7.5 7 82.5 200 11.5 15 22.5 5.5 7.5 Q9.5 250 10 10.5 16.5 5 5.5 52.5 300 6 5 7 4 2 327 4 3 4 2 2 "Position of vertebra" refers to the serial number, beginning with the head-end, of the vertebra measured. Legend: L.V., Length of vertebra, measured from the posterior edge of one dorsal spine to the anterior edge of the one next behind it. T.V., thickness of vertebral centrum in its thinnest part, i.e., near the middle. T. ex. zyg., thickness of vertebra at extreme of posterior zj^gopophyses (articulating processes). H.D.S., height of dorsal spine. W.D.S. , width of dorsal spine. L.R., length of rib. The starfishes are another class of animals which exhibit beautifully this size gradation of repeated parts, both their "tube-feet" and the calcareous skeletal supports being graded proportionately to the tapering arms of the animal. The following table presents a series of measurements of the two organ systems just mentioned, from a single arm of Astrospecten calif ornicus. The dimensions are in millimet- ers, and the series proceed from the proximal to the distal end of the arm. Growth Integration 97 TABLE Series Tube-feet Ambulacral plates Adambulacral plates number Length Length Width Thickness Length Width Thickness 5 3.9 6.4 3.1 1.2 3.8 S.Q 1.0 10 3.7 3.9 2.7 1.3 S.5 2.4 1.2 15 S.5 3.5 2.4 1.3 2.8 2.2 1.4 20 3.1 2.6 2.0 1.2 2.4 2.0 1.2 25 2.2 2.3 2.0 1.0 2.1 1.9 1.1 30 2.1 2.1 1.9 0.9 1.9 1.7 1.2 35 2.3 1.8 1.6 1.0 1.7 1.3 1.1 40 1.7 1.2 1.1 0.9 1.4 1.0 1.0 45 1.8 0.8 1.0 0.6 1.0 0.8 0.9 50 1.3 0.7 0.7 0.5 0.7 0.7 0.6 55 0.9 60 0.8 65 0.7 68 0.5 Not only do these graded meristic series appear in the individual makeup of a great range of animal species, hut they occur in the colonies of many species in which aggrega- tions are produced by budding. Sometimes, as in many al- cyonaria, the size gradations are very obvious, wliile in otlier groups the distinctions are so small as to be discoverable only by close quantitative study. An example of this latter is furnished by the plumularian hydroids. A typical colony of the genus here studied, Torrey writes, "closely resembles a feather, of which the shaft is represented by the stem and the veins by the two ranks of alternating branchlets, or hydro- cladia, corresponding to barbs. Each hydrocladiuni is divided by more or less definite nodes into internodes and bears on one aspect — the same in all hydrocladia — a compact series of hydranths, one to each internode." ^ Without entering into the tabular and graphic details contained in this study, the author's summarized statement concerning one of the tables will suffice: "It will be seen from the table that, as the tip of the colony is approached, not 98 The Unity of the Organism only do the hydrocladia possess fewer and fewer hydroth- ecae, but the dimensions of the latter through the mesial nematophore reaches its minimum more and more rapidly. Since the hj^drothecae, once formed, do not enlarge with age, it is clear that for such colonies as this, there is a limit of growth and a specific form." ^ This correlation and proportionality among repetitive parts is frequently observed within the bounds of particular S^ -V— V a. figure 57 — tentacle of halocynthia johnsoni (schematic; after ritter). a, axis, a', axis of branch, b', b", primary and secondary branches. organs, as for example, in the branching tentacles occurring in various groups. A detailed study of one of these cases was made by me some years ago on the tentacles of an as- cidian. Figure (pi. 12, figure 13) of this study, sup- plemented by the following statement, illustrates the point. "Although this figure is diagrammatic in a way, it is accurate as to numbers of branches. The positions, too, of all the branches and length of the primaries were deter- mined by micrometer measurements, and the secondaries were drawn as accurately as possible." ^ For the rest, the figure (Figure 57) tells its own story. Growth Integration 99 Illustrations from Plants But it is in tlie plant world that those graded scries of homonynious parts in individual organisms are most strik- ingly seen. It occurs in what is perha])s its most typical, least modified expression in the arrangement and size rela- tion of parts in the leaves of many ferns and palms. Hut the compound leaves of innumerable flowering ])lants illus- trate it very beautifully. Figures 58, 59, and 60 {.icacia, Vicia and Cassia) show three types of compound leaves based on the mode of gradation of the leaflets. These might FIOURE 58. ACACIA ELATA. 100 The Unity of the Organism be described as the bi-gradient, the direct gradient and the reverse gradient types, depending on whether the gradation is from the mid-region of the axis both ways (figure 58), from the proximal toward the distal end (figure 59), or from the distal toward the proximal end (figure 60). FIGURE 59. VICIA GIGANTEA. FIGURE 60. CASSIA SP. Almost all simple leaves of seed plants show something of the same scheme. As examples, typical elliptical-entire leaves of the elm and poplar and such typical lobed leaves as those of most oaks may be pointed to. Nearly every twig of a tree which represents a single annual growth impulse, in cases where the growing period is restricted to a small part of each year, presents a size gra- dient in the leaves distributed along the axis. A particularly striking illustration of this is furnished by the California Growth Integration 101 coast redwood, Sequoia sernperiirens (figure f)l), wliere the new segment is sliort, is added end on to the one before it until a considerable succession of segments is ])ro(liifed, and where the leaves are retained for several years. That each segment in these leaves is an annual production is not cer- tain, probably several segments being sometimes formed in a FIGURE 61. SEQUOIA SEMPERVIHENS. single season; but however that may be, that growth occurs in a series of impulses, each of which is sharply recorded in the size gradations of the repeated parts, is obvious enough. It is a familiar fact, too, that in many plants a similar quantitative gradation of the reproductive parts along an axis occurs, but the extent to which this scheme pervades the constituents of the members of the series, even to tlie seeds, appears not to have attracted much interest on the part of botanists. To illustrate this point I present a single set of measurements, one of many which I have collected, 102 The Unity of the Organism of parts of the fructiferous organs of plants. These meas- urements are of Frasera perryi, an abundant annual in southern California and rather specially favorable for such a study in that the fruit stalk is single in each plant, stands up intact and rigid after it is fully ripe and dry, and is al- most mathematically regular in the disposition of its parts. The table was compiled from measurements of a single plant, and three measurements pertaining to each seed vessel are given, namely, the length of the interval on the main axis between each two vessels, the length of the pedicels which bear the vessels, and the length of the vessels themselves. The measurements are all in millimeters. Several other di- mensions might have been taken, which would almost cer- tainly have produced similar results. Series Length of Length of Length of slumber Internode Pedicel Capsule 1 27 36 21 2 19 29 18 3 19 32 18 4 22 34 16 5 23 29 16 6 19.5 28 17 7 18.5 25 17.5 8 17 25.5 17.5 9 19 25 18 10 18 25 16 11 18 21 16.5 12 15 21 16 \S 15 22 13.5 14 15 22 14 15 15 21.5 13 That these gradations hold, at least in some plants, even to the seeds is certain as tlie following tabulation of the weight of seeds from different parts of the seeding axis of a wild mustard plant (Brassica nigra) shows. The figures were compiled from the weights of seeds taken from groups arc in grains. Total weight Base .903 Middle .694> Tip .330 Grorcth Infcgration 103 of twenty ca])sule.s from the bases, niiddK- |)orHons, and dis- tal ends, respectively, of six such stalks. The weights given Number of Seeds Av. Wt. per Seed 950 .0009.0 733 .00088 525 .000()3 This mere glance at an exceedingly common phenomenon in living nature must suffice for the present. Justification for Bringing All These Phenomena Under One Head Probably about the first question that most persons would raise concerning what we have presented would be as to how far the series dealt with have anything to do with one an- other. Especially, we may apprehend, would most biologists question the justifiability of bringing together the meristic phenomena in animals and the repetition of parts in plants. If such a collocation of phenomena must be justified on the basis of known causal factors, then undoubtedly is justifica- tion impossible in the present state of knowledge. But justi- fication of this sort is not called for by the point now oc- cupying us. What concerns us at present is the quite for- mal fact that when any lot of homonymous objects fall into a quantitatively graded series the members of that series liave a fixed relation to the series as a whole. They n\\- not interchangeable with one another. Kach is a function, mathematically speaking, of its set or series. Vertibra /;/ of the python's skeleton, myotome ni of the amphloxus Ixxly, tube-foot 7n of the starfish arm, branchlet in of the ascidian tentacle, leaflet m of the vetch leaf or of the redwood shoot, seed-vessel m of Frasera, seed-lot m of the mustard plant, and m, or any other member you choose from any other 104 The Unity of the Organism series whatsoever, is a determinate thing; it is what it is partly because of its position in the series regardless of whether the physical or other producing agent of the dif- ferent series be the same or wholly different. Even this purely structural formal basis establishes the fact of a measure of integratedness for all individual organisms in which the phenomenon appears. But to leave the subject at that would be superficial and unsatisfactory indeed. However, reflection makes it almost certain that there is some sort of causal basis for the phenomena. This conclusion follows first from the fact that the series result from the growth of the organism, and second from the cer- tainty, at least in many cases, that the continuance of life of the individual involves the maintenance of the series, this in turn involving some measure of metabolic interdepen- dence among the members of the series. Attempted Causal Explanation of These Series For establishing the general truth of this type of inte- gration we need not, in strictness, go any further than we have gone. Nevertheless, the importance of the subject justifies a few remarks on attempts that have been made to explain the series causally. The best known of these comes from botanists, and conceives that the diminishing series of leaves and other structures, seen with more or less distinct- ness almost universally among plants, is due to the increas- ing remoteness of the successive parts from the roots of the plant, that is, from the main source of the plant's food. It is obvious, however, that this explanation is not of general application, since in animals the food does not come from a root system which anchors the organism to its food-yielding medium. Nor is it possible to bring the series in all animals into correlation with a blood circulatory system, as their existence in many coelenterates, hydroids and alcyonarians Growth Integration 105 for cxanipk', wlicre mo circulation exists, sliows. It is al- most certain, too, that the series occur in iiiaiiv plants that liave no sap system such as is assumed by the ])hvsiolo^ical explanation above indicated. Many of the marine al^ae come under this head, a striking example of which is the kel() Mrimary integrative processes in growing 108 The Unity of the Organism organisms that has been made, biology is indebted to C. M. Child. In two recent volumes he has summed up and sys- tematized the elaborate researches prosecuted by him in this field almost exclusively for fifteen years, and has presented his conclusions more fully than in any of his previous writ- ings. The limitation set for the present to the constructive part of our enterprise makes it impossible to do more than touch at a few points the great mass of experimental evidence on which Doctor Child bases his conclusions. Fortunatelv, however, the kernel of the conclusions can be stated rather clearly in a small space. Although (surprisingly, it seems to me) Child refers hardly at all to the graded meristic series occurring in na- ture, to which the preceding pages have been devoted, it can hardly be doubted that the phenomena with which he deals, and calls "axial gradients," come under the same head as do those which have been occupying us. The phenomena which in the first instance Child has been concerned with, have been brought to light mainly through studies on re- generation in many lower animals. But the general con- clusions reached are far broader than this ; indeed they ex- tend to well-nigh the whole scope of organic growth, but especiall}'- to growth which involves elongation either of the whole organism or of certain parts of organisms. Thus the head-tail type of individual, whether the body be segmented as in arthropods and in many worms, or unsegmented as in other worms and in molluscs, is perhaps the most striking exemplification of the axial gradations with which Child deals. The following quotation shows the generality with which he views the matter from the ontogenic side: "Gra- dients in rate of cell division, size of cells, condition or amount of protoplasm in the cells, rate of growth, and rate and seqvience of differentiation are very characteristic fea- tures of both animal and plant development. Such gra- Growth Integration 109 dients are definitely related to the axes of the individual or its parts, and are evidently expressions of axial metabolic gradients. While the existence of such gradients indicates tlie existence of gradients in activity of sonic sort, the various kinds of gradients are not all necessarilv pres- ent where metabolic gradients exist. In some cases the vis- ible gradient may be a gradient in rate of growth or In protoplasmic constitution; in still others a gradient in sequence of differentiation, etc., and sometimes mctaholic gradients exist without any structural indications of their presence. At best these various kinds of gradients arc merely general indications of differences in metabolic rate and undoubtedly in many cases the visible differences along an axis represent something more than differences in meta- bolic rate. The important point is that visible indications of graded differences in metabolic rate occur so generally in definite relations to the chief axes of the body.'' One phase of this general statement is the developmental correlation that various regions of the bodv in manv lower animals have with the head or anterior end, these regions being developmentally dominated, in Child's expression, by the anterior end proportionally to the distance of the re- gion from the end. A typical case is furnished by fiat-worms of the genus Planaria, animals especially favorable for e\[)eriments in regeneration, since they are very hardy to laboratory con- ditions and have great powers of reconstituting themselves from pieces of various sizes, sha])es and ])ositions cut from them. "Any piece of the ])lanarian l)ody," says Child, '"is capable of giving rise to all parts posterior to its own level, whether a head is present or not, but no piece is caj)ahle of producing any part characteristic of more anterior levels than itself, unless a head begins to form first." ^ From a great mass of experimental evidence produced bv Child and others we have the following: "These facts force 110 The Unity of the Organism us to the conclusion that in such experimental reproductions there is a relation of dominance and subordination of parts. The apical or head region develops independently of other parts but controls or dominates their development, and in general any level of the body dominates more posterior or basal levels and is dominated by more anterior or apical levels." '^ A really unique merit in Child's work is the fact that he has given special attention to the connection of these axial gradients manifesting themselves in various structural and functional ways, with the fundamental metabolism of the organism. Several methods of experimenting have been em- ployed to this end, the one most frequently used being what he calls the susceptibility or survival-time method. The es- sence of this depends upon the fact, determined by many ob- servers, "that a relation exists between the general meta- bolic condition of organisms, or their parts, and their sus- ceptibility to a very large number of substances which act as poisons, i.e., which in one way or another make meta- bolism impossible, and that difference in susceptibility may be used with certain precautions and within certain limits as a means of distinguishing differences in metabolic condition, and more specifically, differences in metabolic rate." ^ The demonstration of metabolic gradients by this method depends upon the fact that "death and disintegration of dif- ferent parts of the body usually- follow a regular sequence," this making it possible "to determine the time, not merely of disintegration of the whole animal, but of the various re- gions of the body." ^ Another way of showing difference in rate of metabolism in different parts of the organism is by the use of the biom- eter, an apparatus for estimating minute quantities of carbon dioxide, recently devised by S. Tashiro in connection with his important researches on carbon dioxide production in nerves. By these methods it is shown, pointing to a single Growth Integration 111 instance, that in pieces of a flat-worm isolated by cutting "the rate of metabolism is higher in long anterior pieces than in posterior pieces of tlie same length.'' ^'^ Starting from this low but seemingly universal level of integrative phenomena in tlie individual, Child foniuilates views of the nature of organisms that agree verv well with the organismal standpoint upheld in this volume. lie writes: "Tlie organic individual apj)ears to be a unitv of some sort. Its individuality consists primarily in tliis unity, and the process of individuation is the progress of integra- tion of a mere aggregation into such a unity, for this unity is not simply the unity of a chance aggregation, but one of a very particular kind and highly constant character for each kind of individual. In all except the simplest individ- uals it determines a remarkable degree of uniformity and consistency, both in the special relations of parts and the order of their appearance in time, and also in coordination or harmony of functional relation to these parts after their development." ^^ Meristic Gradients and Metabolic Gradients Both Phenomena of Groieth Integration In view, then, of the exceedingly wide ])revalence in living nature of axially disposed meristic series quantitivcly graded, and of the equally wide or even wider })revalence of axial gradients on the basis of metabolic activity, the gradients of both sorts arising as- fundamental growtli plie- nomena, it appears im])ossible to avoid recognizing our first category of integration, namely, groxcth integration, as a})out the most simple and ])rimal and universal of all these categories, at least for nudticellular organisms. It seems as though the other kinds of differentiation and integration are superposed, as one might express it, upon this primordial kind. To a consideration of the other, su])erimpos('d inte- 112 The Unity of the Organism grations we now pass, taking them again in their seeming order of obviousness. REFERENCE INDEX 1. Torrey 139 Q. Ritter ('09) 71 3. Robertson 612 4. Moeser 373 5. Child (2) 65 6. Child (1) 213 7. Child (1) 215 8. ChUd (1) 9. Child (1) 10. Child (1) 11. Child (2) 66 77 73 2 Chapter XVlll CHExAIICO-FUNCTIONAI. INTEGRATION Functional as Contrasted with Growth Integration \ SSUMING Child's theory of metabolic gradients to be ^ *"well grounded, we are furnished thereby with one im- portant insight into the chemical processes involved in the unit}^ of the individual organism. But that process is con- cerned primarily with the growth, with the production of the individual. The question now is, are there chemical proc- esses the object of which is to maintain the functional unity of the complete or nearly complete individual.'' Are there chemical operations the office of which is to preserve a proper interrelation among the parts of the organism as these perform their special offices.'^ That such is to some extent the significance of most if not all internal secretions as usually understood is indicated by the fact that the functional disturbances attending re- moval of the thyroids or other glands from various animals ; and by the further fact that where internal secretions play a part in development, their action is rather tliat of stinuila- tor, or at least modifier, than of true producer. The conception of internal secretions as being at Kast as much regulators of physiological function as of growth is illustrated by cases of hypopituitarism of the post- adolescent type, like those described by Gushing, for ex- ample. In the series of cases of disease due to "jiituitary deficiency" the first symptoms appeared when tlie subjects were from thirty to forty years old. 113 114 The Unify of the Organism The Conception of ''Internal Secretions" The nature of the phenomena now to be considered, and their significance for our discussion make it desirable to think about these secretions from tlie broad standpoint first stated, according* to Ba3^1iss, by Brown-Sequard and d'Arson- val, namely, as materials produced by any living cells or tissues wliich are discharged into the blood or lymph and have specific effects on other parts or functions of the or- ganism. Regarded thus it is now known that many cells of the organism produce internal secretions. Although we are more concerned with function than witli structure in this discussion, our purpose will be best served by beginning with a mor2:)hological classification of the secretion-pro- ducing cells. They may be divided into two categories, those which are disposed into definite organs, or glands, the ductless glands of long standing in anatomy ; and those which are not assembled in such organs. Knowledge of this second class of cells is of recent date, and is fuller from the functional than from the structural standpoint. The chief glands, to which the name Endocrine has lately been given by Schafer, are now so well known as hardly to need men- tion. They are the thyroid apparatus, including the thy- roids and the parathyroids, the suprarenal body, the pitui- tary body, and probably the thymus and pineal bodies. Cells now known to produce internal secretions but which are not arranged in glands are certain cells of the pancreas scat- tered among the pancreatic cells proper ; certain cells of the alimentary mucous membrane; the interstitial cells of the ovary and of the testis, and probably certain cells of the placenta, of the mammary gland, and of the uterus. Following our usual course of making the treatment merely illustrative rather than aiming at exhaustiveness, our selection will include one example from each of these groups. From the glandular category we take the thyroid Chemico-Functional Inteyration 115 apparatus, and from tlie non-glandular a jxjrtion of the alimentary nuicous membrane, namely, that of the duo- denum. Effects of liemoving the Human TliifroUl for Curative Purposes As definite knowled^-e of the ^'reat [)hyslolo^ieal impor- tance of internal secretions beg-ins with human surgery — with operations on the thyroid aj)paratus — we may well begin our study here. This is the better starting })oint in that there is no more striking illustration of how great a part of the whole organism ma}' be implicated in the action of internal secretions than is afforded by the jjrod- ucts of the thyroids and parathyroids. The subject first came into clear lif^ht in the early eii^hties of the last century through the experiences of Swiss sur- geons, Theodor Kocher and J. L. Reverdin esj>ecially, who removed the thyroids to cure goitre, this disease being s})e- cially prevalent in some parts of Switzerland. The })atients operated on were found to improve ra])idly for a time after the operation, but later untoward symptoms began to mani- fest themselves. Because the variety and ]X'rvasiveness of these symptoms in a typical case are highly instructive for us we present them in detail, selecting a description from Human Physiology by Luciani: "Patients who have under- gone total thyroidectomy . . . experience the initial symp- toms of glandular deficiency either at once or at latest some weeks after the operation. They feel weak, com])laiii of heaviness of the limbs, and more or less diffuse dull pains, ])articularly in the legs, which may iH'come acute and assume tlic character of ])airis in the bones. "Other more serious symptoms arc gradually associati'd with the preceding. After four or five months the face and the extremities swell and become cold, the nmscles are 116 The Unity of the Organism torpid, sometimes rigid, often exhibiting muscular tremors, and are incapable of carrying out any delicate manual acts of precision. At first the swelling is variable; it is more pronounced in the morning than in the evening, but steadily increases until it becomes permanent. It is not ordinary oedema, in which percussion with the fingers leaves a depres- sion ; it is a hard and elastic swelling. It is specially local- ized in the hands, feet and face, where it produces a char- acteristic alteration of the countenance. The lower eyelids are the first to present a sacculated, semi-transparent swell- ing, which is hard to the touch ; then the infiltration spreads to the folds of the face, which become smoothed out ; to the nose, which gets rounded; to the lips which swell, and bulge outward, saliva dribbling from tliem. The features are coarsened and expressionless like those of a cretin. "The mental functions accord with this appearance, since they are blunted, so that the patients lose their memory, become deaf, taciturn, melancholy, self-absorbed, and reply extremely slowly to questions. They further complain of slight but perpetual headache ; feel an almost constant sen- sation of cold, which is most acute at tlie extremities ; at times they are seized with vertigo, and may even lose con- sciousness. "All the symptoms become still further aggravated. The whole body may grow more bulky from the extension of the swelling. The skin loses its elasticity, can only be picked up in large folds, and becomes dry owing to defective capacity for sweating. The epidermis desquamates in more or less extensive lamellae, particularly on the hands and feet ; the hair turns grey, falls out, and gets constantly thinner. "The heart functions weakly, but with ordinary rhythm; the pulse is small and thready. Examination of the blood shows nothing constant ; but there is often a more or less pronounced and progressive oligocythsemia, which undoubt- edly contributes to the characteristic pallor of the skin, Chemico-Functional Integration 117 this being of the earthy, yellow-spotted hue peculiar to cretins. "The respiratory rhythm is ahnost ahvays normal ; tlie digestive apparatus functions well, as also the urinary system. The spleen is not enlarged." ^ This complex (syndrome in medical terminology) of manifestations is known technically as cachexia thyreo- priva. Later experience by other surgeons with the same opera- tion discovered that in some cases the effects are much more acute and rapid, and may be replaced by what has been called "tetany" (though having little in common with ordi- nary tetanus), ending in death more often than otherwise. Experimental Thyroid Excision in Normal Lower Animals No sooner had the far-reaching influence of the thyroid for tlie human organism begun to be recognized in this way than experimentation on inferior mammals was invoked for further light on the subject. Moritz Schiff, the ground- breaker in this field, published in 188-i the results of the removal of the thyroid from a large number of dogs. In all cases where the whole thyroid apparatus was excised the dogs soon died after a run of such symptoms as tremor, spasms, and convulsions. Nor did SchifF rest content with merely ascertaining the effects of removal, complete and partial, of the thyroid apparatus. He found that these effects could be entirely prevented by grafting a portion of the gland under the skin or into the body cavity of tlu' animal before the thyroid operation, or by injecting thyroid juice into the blood or lymphatic systems, or by feeding raw thyroid to the dogs. The story of how these experiments led to the now widely practiced treatment of myxo^lema with thyroid or thyroid extract would be out of ])lace here, though it should not be passed wholly unnoticed. 118 The Unity of the Organism So an enormous mass of evidence, experimental, surgical and clinical, is now in court demonstrating that for some animals at least, among them being the human and the canine species, products of the thyroid apparatus are in- dispensable to the normal life, the symmetrical growth and balanced physiological activities of the organism. That the apparatus is essential to tlie "Hormonic Equilibrium" of the organism in some animals is beyond question. While no pretense can be made at an exhaustive exami- nation of this evidence two phases of our discussion make it desirable to cary the examination on the manifestational side a little farther. One of these is the importance of making as objective and emphatic as possible the extent of the manifestations in the individual ; the other is the ques- tion of the generality, taxonomically speaking, of the thy- roid apparatus. In the interest of the first of these I present, verbatim, the report of a single case of complete thyroidectomy, the animal in this instance being a fox. The individual concerned was a female less than one year old. "Oct. 28. Glands removed; good recovery. "Oct. 29- Normal, but does not eat. "Oct. 30. Salivation, rapid breathing, strong tremors and tet- any from 7 A. M. to 2 P. M.; quiescent but weak during the rest of the afternoon. "Nov. 1. Normal, but rather weak; eats; no sign of tremors or salivation during the day. "Nov. 2. Restless; slight tremors; dyspnoea; does not eat. "Nov. 3. Some depression, but no tremors or salivation until 4 P. M. ; does not eat. At 4 P. M. spasms appeared and con- tinued unabated as long as observed (7 P. M.). "Nov. 4. Found dead at 4 A. M. Post-mortem examination revealed no parathyroids nor accessory thyroids." ^ As to taxonomic range and character of manifestation of thy- roid influence, much diversity might have been anticipated on general natural history grounds. As far as investigations have gone they realize these anticipations. A summary of results will serve our purpose, and this is at hand in Schafer's volume already Chemico-Fujicfional Integration 119 cited. Concerning the effects of removal of tlie tliyroid appa- ratus he says : "The most acute symptoms are exliihited hy carnivora such as dogs^ cats, foxes^ and wolves (Vincent), and tlie young of lierhi- vora (v. Eiselsberg, Sutherland Simpson) and are of a nervous nature. . . . Some species exliibit no symptoms whatever — at least when the operation is })erfornu'd on the adult. Horslcy states that this is the case with birds and rabbits; but according to Gley, the latter are affected if care is taken to find and re- move all four parathyroids, and Dp3'on and ,Jouty obtained tyi)ical tetany in hens which had been parathyroidectomized. . . . Ac- cording to Vincent and Jolly badgers are totally unaffected by complete removal of both thyroids and parathyroids." ^ From the anatomical characteristics of the organs, and from tlie known effectiveness of minute portions of them, such statements as the last must be taken with re- serve. Although these results show by their diversity that an enormous amount of study remains to be done on the comparative side, they leave no question that the secretion of the thyroid af)paratus is important for the general health and equilibrium of most animals in which it occurs. The measure of tliis importance in the eyes of some authori- ties is seen in sucli a statement as, "No cell anywhere in the body can reach morphological perfection without thyroid stimulus." * The Internal Secretion of the Duodenal Mucous Mcnihraue We now pass to an examination of thi- effects of the internal secretion of the duodenal nuicons lucnibrafu". 'I'his particular secretion is selected for the n-asons that it is, according to Bayliss, one of its discoverers, "the most typical of all the chemical messengers''; that it was om- of the first to be investigated; and that it is one of the Uw which have been isolated as definite substances. IW The Unity of the Organism The mode of operation of this secretion is tersely stated by Bayliss : "Food entering the duodenum causes the pro- duction of a special substance which enters the blood and excites the pancreas to pour into the duodenum a digestive juice. ** That the presence of various substances, especially acids, in the duodenum, induces a flow of pancreatic juice was known when Bayliss and Starling began their work in this field; but up to that time the excitation of the pancreas to such action was supposed to be through a nerve reflex. These investigators had reported in 1902 ^ that acid in the duodenum is able to cause the pancreas to secrete after nervous communication between the intestinal wall and the pancreas is excluded. They went further and obtained an extract from the duodenal mucous membrane which, being injected into a vein, induced a copious flow of pancreatic juice. The substance, whatever it is, which acts thus they call secretin. It has been surmised by a few physiologists that the eff'ects are not due to the direct action of the secre- tion on the pancreatic gland-cells, but that the influence is exerted through the vaso-dilator mechanism. But this surmise is negatived by the demonstration that the secretin will induce the flow of pancreatic juice while it does not alter the blood pressure. The case seems, then, fully estab- lished, and is so clear-cut and relatively simple an instance of the coordinated functioning of two wholly distinct parts of the body through chemical means, that it is desirable to get sharply before us the known steps in the process. In the course of normal digestion, food acidulated in the stomach passes into the duodenum. Here, probably in virtue of its acidity, it acts upon the cells of the mucous membrane in sucli a way as to induce them to produce a substance which is discharged, not into the intestines, there to take its part in digestion, but into the blood. By the blood stream the substance is carried through its whole Chemico-Functional Integration 121 circuit, lience tlirough the lungs and so on, around to the pancreas, the typical gland-cells of which it excites into activity, so that the pancreatic juice, an "external" instead of an ''internal" secretion, is poured into the duodenum to exercise its digestive office on the same food which started the cycle of activities. It was with tliis substance particularly before tlieir minds Hiat tlic authors adopted the name Iwnnone to designate substances which act tlius. "The group of substances re- ferred to," says Bayliss, "which includes adrenaline and the various internal secretions, is characterized by the prop- erty of serving as chemical messengers, by wliicli the activity of certain organs is coordinated with that of others. They enable a chemical correlation of the functions of the organ- ism to be brought about through the blood, side by side with that which is the function of the nervous system." ^ Tliis reference to the side-by-side activities of chemical messengers and nervous system in integrating the organism touches a subject of the utmost importance. Considera- tion of it must, however, be deferred until we have looked a little more into the nature of hormones. The Nature of the Actii*e Substances in Internal Secretions That the peculiar iodine-rich albuminous substance ob- tained from the thyroid by Baumann in 1895 and since observed by other investigators, contributes in some essen- tial way to the action of the secretion of tliis gland is the belief of apparently a large majority of autliors (Bayliss, Kppinger, Howell, etc.), but not of all (Luciani). In view of the uncertainty on the point Schafer's proposal "to ex- press our ignorance by a term which implies no theory" may well be accepted, with the proviso that the term pro- posed be really taken as evidence that sowefhing though not everything is known about the substance. A part of 122 The Unity of the Organism the proposal is worth quoting. "I propose therefore pro- visionally to apply the word thyrine to denote the active principle, whether it be identical with or contained in the iodothyrin of Baumann or not." ^ Thyrine then becomes the name of a substance the source and some of the activities of wliich are known, but whose main physical and chemical attributes are unknown. Concerning the mode of action of thyrine there are sev- eral divergent views, all based on some evidence and so perhaps not entirely antagonistic. Is the antitoxic theory of Luciani ^ partly right, right as regards the parathyroid secretion (Moussu, Vassale and Generali), and partly wrong, wrong as to the secretion of the thyroid proper, this being trophic rather than antitoxic? ^^ ^lay there not be more in the enzymic theory suggested some years ago, than later writings have been inclined to favor .^ Does the fact that internal secretions seem to be simpler than enzymes, as indicated by their greater resistance to heat, preclude the possibility that their normal mode of action is of the enzyme type after all.? That is, may it not be necessary to extend the conception of enzymic action (which is surely generic anyway) to include the various sorts of activity presented by hormones, understood in the sense given it by its origi- nators ? But neither can the resemblance of internal secretions to drugs, so far as their action is concerned, be overlooked. This has been dwelt upon by Scliafer ^^ and has important bearings on the problems of the origin as well as on the chemical nature of the substances. Another aspect of the mode of action of internal secre- tions is that of whether the effects are to stimulate or inhibit the activity of the organ or tissue on which they operate. Schafer and others make a special point of this, directing the attention to the fact, by way of illustration, that the adrenaline of the suprarenal medulla causes contraction of Chemico-Functional Integration 123 the plain muscle of the blood vessels and inhibition of that of the intestines. ^^ The distinction has an undoubted natu- ral grounding', and so is in tlio interest of acenrate doscriji- tion and clear conce})tion. As to the actual chemical composition of internal secre- tions, knowledge is exceechngly meager. More is known about adrenaline, the active [)rinciple of the su])rarenal gland, than about that of the secretion of any other gland or tissue. This was isolated by the Japanese chemist Jokichi Takamine in 1901, and has since been more fully examined by several investigators, notably by T. B. Aid rich. It is described as a micro-crystalline substance occurring in at least five crystal forms. Aldrich assigns to it the em- pirical formula CoHjoNOo, this structure placing it not far from tyrosin in the benzene or aromatic series. Of special interest is the astonishingly minute quantites which produce physiological effects. According to Aldrich 0. 000001 gram of an aqueous solution of the chloride per kilo of body weight injected into the blood system raises the blood pres- sure 14 mm. of mercurv.^^ The chemical nature of Tethelin, lately isolated from the anterior lobe of the pituitary of the ox, has been studied bv its discoverer, Robertson. It is described as white or pale cream colored, readily powdered, highly deliquescent, and having a greasy odor and slightly acid reaction in aqueous solutions. It contains 1.4 per cent of phosphorus and four atoms of nitrogen for everj^ atom of phos]ihorus. The phospliorus-nitrogen content of the substance is con- sidered by Robertson as specially significant, since this seems to ally it chemically with "j)hytin," a substance found in the rapidly growing ])arts of plants, and in milk. The natural suggestion is that the growth-promoting substances in plants, milk, and the pituitary secretion are chemically related. 124 The Unity of the Organism The Close Resemblances and Interrelations of the Different Internal Secretions Even the meager, merely illustrative examination of in- ternal secretions we have been able to make brings out the close resemblance there is between the several endocrine glands, and also between the physiological effects of the various secretions. These resemblances suggest an intimate organic interrelationship among all the internal secretion- producing parts of the body. All investigators in this field, no matter to how restricted a section of it their efforts are primarily directed, seem to come upon the interdependence of the sources and activities of hormones. To illustrate. Gushing, whose central interest has been the hyphophysis, is led to conclude that experi- mentally induced hyphophyseal deficiency works histologi- cal changes in many if not all tlie other ductless glands. It is not sui^prising, consequently that far-reaching theories have been elaborated on the basis of these relationships. Bayliss refers with approval to Elliott for the conserva- tism with which he sums up the present state of knowledge on this aspect of the general subject. But even so, features are pointed out "which suggest a common bond" : "(1) Carbohydrate metabolism is influenced, not only by the pancreas, but also by the thyroid in super-activity, in acromegaly, and by the injection of adrenaline. "(2) Growth is affected by the testis and the cortex of the suprarenals, arrested by the absence of the thyroid. "(3) Nervous implications. "(4) The pituitary becomes hypertrophied when the thy- roid is removed. Acromegaly may lead to enlargement of the thyroid." ^^ At the other extreme of what may be regarded as legiti- mate scientific theorizing, we have the views of Sajous, who believes research will finallj^ demonstrate a relationship be- Chemico-Fimctional Integration 125 twcen all the ductless glands the combined functioning of which dominates most of the activities, normal and patho- logical, of the organism. Sajous' elaborately worked-out theories of internal se- cretions, especially in their relation to disease and medical practice, are opposed at many points to prevailing opinion based on present day research. Nevertheless regarded from the standpoint of general biology there would seem to be much merit in his effort on the one hand to find a common ground in the metabolic processes for all the phenomena at- tributed to endocrinal activity ; and on the other hand to find a more consistent morphological and physiological basis of definition and classification of internal secretions and the structures which produce them than has yet been recognized. For example, whether Sajous is right or not in contending that the pituitary body does not produce an internal secre- tion, certain it is tluit the non-glandular structure of its posterior part, extracts of which alone have slowing effects on the heart, is strongly suggestive to the critical naturalist that the inclusion without qualification of this part at least of the organ among the endocrine glands is an instance of what is known to taxonomists as "lumping" in classification — a kind of practice that advance in knowledge always finds to be inadequate for purposes that are critical. Sajous' late summary of his views is highly suggestive to the general biologist, even though it is excessively theoretical in some parts. As far as a much interested outsider can judge, tlie ]i res- ent state of understanding of the relationships among the internal secretions is set forth with exceptional judiciousness by Waller. "There can be little doubt," tlie author o])ens his discussion by remarking, "that the various internal secre- tions are most closely correlated, yet perha])s the most dif- ficult, and also the most fascinating problem of present day medicine, is to assign to each its proper and riglit share of 126 The Unity of the Organism importance." ^^ This statement, coupled with the fact that one of the main objects of the discussion is to display the many contradictions which the author's large experience as a i3ractitioner has found in the action of the internal se- cretions, is about the most striking, and from our stand- Yfomi most significant tiling about this paper. As one illustration of the agreement of action of the se- cretions, or at least of the influence of the endocrine glands, it is pointed out that changes in calcium metabolism have been obsers^ed after removal of the thymus ; in disease of the pituitary and of the pineal bodies ; after castration ; after ovariotomy ; after removal of the suprarenals, and after re- moval of the thyroids and parathyroids. Of the numerous instances of contradiction which he brings out, we mention only that concerning tetany. This he shows may result from either removal of the thyroid or from an overdose of thyroid extract. The explanation of the contradictions in the action of a mven secretion favored by the author is that of the "varying influence of the other internal secretions." But the descriptions given seem to leave no doubt that diff'erence in type of individuals also comes into the explanation. Thus among children afflicted with enlarged tonsils and adenoids, the two distinct types dependent upon the character of the s^^mptoms, is a case in point. One type is dull and stupid, stunted in growth, has dry coarse skin, and may display symptoms of rickets. The other type is vivacious pliysically and mentally, given to peevishness, irritability and quick fatigue, and always want- ing a change of activity. This type is over-tall for its age, perspires readily and is fine-skinned. Both types of cases are benefited at least for a time. Waller says, by treatment with thyroid extract. Concerning the general nature of the interdependence among internal secretions, this author's views seem to me so eminently sound that I cannot refrain from quoting them in CJiemico-Functional Integration 127 some fullness: "Considerable stress has been laid upon the antagonism of different internal secretions by various au- thors. I believe we should gain a truer insight into their working if we dwelt rather upon their harmony. It does not strike me as a very high conception of the human organism that health should consist in the balance of dissentient or antagonistic forces. It would seem far more ideal that all the internal secretions should work together for the common good of the organism, and that wlicn some special demand is made upon a particular gland the others will work in har- mony with it. Every gland is probably necessary for the perfect activity of the rest, and the harmony between the glands is demonstrated by physiological experiments. . . . When it is found that the removal of an organ constantly induces either atrophy or hypertrophy of some other organ, we can reasonably deduce that in the first case the organ removed is essential to tlie welfare of the one that atrophies in its absence, and in the second case that the hypertroph^'ing organ is endeavoring to replace the lost one, in some de- gree, and that therefore the two organs have a kindred function." ^^ As an example of the first case, the fact is cited that the removal of the thyroid or of the anterior part of the pitui- tary induces the atrophy of the testicles or the ovaries. The second case is illustrated by the hypertrophy of tlie supra- renal from the removal of the thvroids, and also bv the hypertrophy of either the thyroid or tlie pituitary on re- moval of the other. "The demonstrated facts of liyper- trophy," we read, "clearly point to an entente or even a triple alliance between thyroid, hy]'>ophysis and suprarenals. And the genital system is absolutely deix^ndent upon the integrity of these three." ^^ Stating now, in a single paragra])li, the results of inves- tigations in this field, we have: The different parts and ac- tivities of the organism are maintained in their normal state, 128 The Unity of the Organism both as to the essential nature of each, considered individ- ually, and as to their relation with one another, by a number of exceedingly powerful and subtle chemical substances (in- ternal secretions) which are produced by certain parts, are passed into the blood, and by it are carried about over the whole organism to exert their appropriate influences on other parts and functions. Because of the peculiar way these substances do their work, they have been called chemical messengers, or to have a distinctive name, hormones. Relation Between the Internal Secretory and Nervous Systems But no physiological truth is better known than that one of the main offices of the nervous system is to correlate the organs and parts of the body with one another. It is but natural to suppose, therefore, that if there is a chemical scheme for accomplishing the same end, the two are in some way closely related. That the relations which exist between the cerebro-spinal nervous system, the autonomic nervous system (including the sympathetic), and the internal secretions, constitute one of the most important subjects in the whole physiological do- main, at the same time that it is one of the most recondite and difficult to investigate, has come gradually to view through the work of the last few decades. We will try to extract enough from the mass that has been written on the subject, to illustrate the principles involved. The modern period of knowledge of what was formerly but rather in- definitely included under the term sympathetic nervous sys- tem, has revealed that we have to do with a portion of the general nervous mechanism which in reality is a subdivision of a larger category. Chemico-Functioiial Integration 129 Composition and Nature of the Autonomic System The name autonomic was given to this category by Lang- ley. "The autonomic nervous system," he says, "means the nervous system of the glands and of the invohuitary muscles ; it governs the 'organic' functions of the body"; and further: "The word implies a certain degree of independent action, but exercised under the control of a higher power." ^** l^ay- liss adds: "It is necessar}^ to be quite clear that the au- tonomic system includes the sym]:)athetic, since some writers abroad use the name as applying to all the visceral nervous system other than the sympathetic, speaking of sympathetic and autonomic." ^^ Perhaps the most important single fact which differen- tiates the autonomic from the cerebro-spinal system is the intercalation, everywhere in the autonomic system, of an extra neurone between the cerebro-spinal ners'e and the part innervated. Cannon states this distinction very clearly : "The skeletal muscles receive their nen-e supply direct from the central nervous system, i. e., the nerve fibers distributed to these muscles are parts of the neurones whose cell-bodies lie within the brain or spinal cord. The glands and smootli muscles of the viscera, on the contrary, are, so far as is now known, never innervated directly from the central nervous s^'stem. The neurones reaching out from the brain or spinal cord never come into immediate relation with the gland or smooth muscle cells ; there are always interposed between the cerebrospinal neurones and the visceral extra neurones whose bodies lie wholly outside the central nervous system." ^^ Cannon's suggestion that these interposed neurones may function as transformers for impulses received from the cere- brospinal system should be noted here. Three sharp subdivisions of the autonomic nervous sys- tem are recognizable. One is known as the vagal or cranial 130 The Unity of the Organism autonomic, because it is largely made up of fibers from the vagus, or tenth pair of cranial nerv^es. Another is the sym- pathetic, or better, the thoracico-lumbar autonomic, be- cause its fibers originate from the great visceral sympathetic ganglia. This is by far the most extensive of the three sub- divisions, and is the only one that is distributed to all parts of the body. The third is the sacral autonomic. As its name implies, it is quite restricted in extent, its fibers being dis- tributed to the extreme distal end of the intestine, the urin- ary bladder, and some of the external genital organs. But the differences between the three which are most important for us are physiological, a particularly important difference being that the thoracico-lumbar di\'ision acts antagonistic- ally to both the end divisions. Stimulation of the fibers of the sympathetic has just the opposite effect to the same stimulus applied to the fibers of the others. "The sympa- thetic fibers check, the vagal autonomic fibers excite, the movements of the intestines ; the sympathetic dilates, the vagal autonomic contracts, the pupil ; the sympathetic hastens, the vagal autonomic slows, the heart." ^^ The sacral contracts the lower part of the large intestine and re- laxes the outlet of the bladder, while the sympathetic relaxes the same part of the intestine and contracts the same part of the bladder. Cannon states the general principle thus : ''When the mid-part meets either end part in any viscus their effects are antagonistic.'* ^^ While the incompleteness of knowledge in this field needs emphasizing, yet that knowledge is sufficient to put some of the main features beyond question, and to make clear the great importance of the subject and of fuller knowledge on it. Touching these general aspects Professor L. F. Barker writes : "While we do not yet understand the exact mechan- isms of association among the activities of the cerebrum, the endocrine glands, and the reciprocally antagonistic au- tonomic domains and their end-organs, we can begin to see Chemico-Functional Integration 131 the paths which must be followed in order tliat more exact knowledge may be gained." -'"^ Experimental Evidence of Connection Between the Adrenal Glands and the Nervous System Some of the most important information we have in this field is furnished by Cannon and his collaborators concern- ing the secretion of the adrenals and its relation to the autonomic and central nervous systems. It had been proved before Cannon began his investigations that adrenin injected into the blood has exactly the same effect on certain parts of the organism as does the sympathetic autonomic nerves with which the same parts are supplied, and that the effect of the secretion is direct and not through the nel'^'es. In other words, it had been proved that the organism has two methods by which the same activity of certain of its parts can be induced, one nervous, the other chemical. Thus the dilation of the pupils, the erection of hairs, the inhibition of activities of the alimentarv^ canal, and the liberation of sugar from the liver can be induced either through sym- pathetic autonomic centers or by the secretion of the adrenal bodies. This in itself was important evidence of interrela- tion between the nervous system and internal secretory sys- tem. But the experimental researches prosecuted in Can- non's laboratory have proved that a connection exists be- tween the autonomic-adrenal phenomena and the cerebro- spinal system through the sensory nen-es, and with the psychic life of the animal; and have shown the jirobable sig- nificance of the entire scheme for the life of tlic organism as a whole. To be a little more specific, they have proved: (1) That strong excitation of sensory nerves stimulates reflexly the adrenal glands and causes them to pour an increased amount of adrenin into the blood. 13^ The Unity of the Organism (S) That emotional excitement (as the fright of a cat by a dog) similarly increases the flow of adrenin. (8) That this increase of adrenin in the blood may in- crease the liberation of sugar from the liver into the blood to such an extent as to make sugar appear in the urine, thus demonstrating a true "emotional gl^^cosuria." (4) That the increased adrenin of the blood thus pro- duced is probably advantageous to the organism in that it enhances its ability to meet special stresses that naturally accompany special excitement, as of fear, anger, or pain, this advantage consisting partly in augmentation of the working energy of the muscles, probably through the sugar delivered to them, and in increasing the coagulability of the blood, thereby reducing the danger from bleeding wounds. Summing up his conclusions as to utility. Cannon writes : "These changes in the body are, each one of them, directly serviceable in making the organism more efficient in the struggle which fear or rage or pain may involve; for fear and rage are organic preparations for action, and pain is the most powerful known stimulus to supreme exertion. The organism which with the aid of increased adrenal secretion can best muster its energies, can best call forth sugar to supply the laboring muscles, can best lessen fatigue, and can best send blood to the parts essential in the run or the fight for life, is most likely to sursdve." ^^ But fear and rage are, one hardly need be reminded, in part psychic phenomena, and hence inseparably connected with the higher centers of the cerebrospinal nervous system. Though in the main reflex and automatic, they are neverthe- less to some extent subject in man to intelligent control. Thus the way is open for a measure of rational understand- ing of the structural-functional means by which human be- ings "tap," as William James would say, and bring under direction those remarkable "reservoirs" of ordinarily unused energy about which everybody knows something from his Chemico-Functional Integration 133 own experience, and upon wliieli nobody lias written more intelligently than James. An excellent beginning has been made, then, in the ex- perimental demonstration of the integration of the endo- crinal and common glandular systems, the blood circulatory system, the autonomic and cerebrospinal nervous systems, and the emotional-psj^chic life of animals. Clinical Evidence of Adrenal-Nervous Connection But important knowledge and general views in this field are also coming from clinical medicine, and pharmacology. A general presentation of the results reached down to 1913 is contained in Innere Sekretion und Nervensystem^ by H. Eppinger and others. A particularly significant body of evidence coming from this source concerns the relation between the sympathetic or middle autonomic nervous ap- paratus and the two end autonomic systems, the cranial and sacral. These two groups act, it will be recalled, antagon- istically to each other. Eppinger and others have shown that the thoracico-lumbar, or sympathetic, and cranial, or vagal systems differ in susceptibility to stimuli In different individuals, and perhaps in the same individual at different times, thus making the two groups what Is called sympa- theticotonic and vagotonic with reference to each other, de- pending on whether the sympathetic or the vagal is the more susceptible to stimuli. This difference can be demonstrated by the administration of various drugs, as adrenin and pilo- carpin. But it is known, according to E})pinger, that the thyroid toxin stimulates both the sympathetic and the vagal. From this it results that over-stimulus of either may occur through this source, and go to the extent of ]M'oducIng the characteristic symptoms of Basedow's or Graves^s disease (rapid heart beat, exophthalmia, diarrhea, etc.). Tiiese symptoms may occur in varying degree, dej)ending on 134 The Unity of the Organism whether the patient is sympathetico- or vagotonic, the sym- patheticotonic type of the disease being characterized by marked protrusion of the eyeballs, especially rapid heart beat, absence of sweats, diarrhea, and disturbance of the respiration ; while the vagotonic type is characterized by slight protrusion of the eyes and increase of heart action, by outbreaks of sweat, diarrhea, and by faultiness in the respiratory rhythm. While some observers, like Falta, do not believe the facts now known can be definitely classed in this manner, the ef- fort, justified by some positive knowledge, has at least the merit of specifying to some extent the intricate reciprocal action between the thyroid apparatus and the nervous sys- tem, and also between the different portions of the auto- nomic system; and to this extent all students of the subject bear witness. Thus Falta : "In my opinion everything speaks for the fact that in Basedow's disease the entire nervous system is in a condition of over-excitement and that the pictures presented by the vegetative nervous system are as uncommonly manifold and always changing." "^ The indication of prime importance in this is that in these antagonistic divisions of the autonomic nervous and endo- crinal glandular systems, operating together with the other portions of the organism, there is a balancing-ofF or equil- ibrating apparatus through which the whole complex of vege- tative functions is carried on, all of which in turn are con- nected with the ps3^chic functions. Probably- no better il- lustration can be found of the conception of the organism as fundamentally dynamic. According to this conception nor- mality, both in function and in structure, consists not in rigid, invariable activities and organs, but in a ceaseless play of constitutively antagonistic forces and structures. By this conception the whole life of the organism, physical and psy- chical, may be crudely likened to the performance of the tight-rope walker, which depends on numberless balancing Cliemico-Functional Integration 1.'3.") activities. Let the performer be reallv motionles.s in every part for one instant, and lie falls. The treatment of tetany and its relation to internal se- cretions, especially to that of the thyroid, by Eduard Phleps in the work now under consideration, is another excellent il- lustration of how interpretation may run In accordance witli this conce])tion of the animal organism. The essence of the section, as touching this question, is contained in tlie fol- lowing : "On the ground of clinical symptoms authoritative clin- icians like Eulenburg, Kahler and Nothnagel explained tet- anus as a disease of the entire nervous system. Later it was proved that this disease was not due to primary organic changes of the nervous system, but to secondary functional disorders. . . . The view of those authors, who refer the disease to the sim])le effect of a substance of the epithelial granules acting normally and continuously on the whole nervous system, finds here a further development of that old theory because for them the clinical picture of a regular grouping of nervous stimulus- and response-phenomena arises from an impairment of the close functional relation between the nervous system and the epithelial granules (Mac- Callum, Chvostek jun., Biedl, Eppinger, Falta, Rudinger, Jonas, et al.). In agreement with these authors we con- ceive the action of the epithelio-secretive substance as that of a hormone in the sense of Starling and Bayliss, which must have its essential point of attack on certain reflex stations of the central nervous system." ^^ Taking cognizance, now, of the fact that most if not all the cells known to produce internal secretions arise embry- onically from epithelium, as does also almost all nervous tissue, we have the suggestion of a deep-seated combination scheme, chemical-and-nervous, for integrating the organism. The best investigated example of what is here referred to is the suprarenal bodies. It is now fully established that the 136 The Unity of the Organism inner or medullary portion of the organ, the part which pro- duces the adrenin, is developed from the same neuroblastic mass out of which the sympathetic autonomic ganglia arise. Furthermore, it seems bej^ond question that the so-called chromophil, or sometimes the adrenin granules in the chief cells of the functioning gland play a fundamental role. Com- bining these facts with the equally well ascertained facts that the cortex of the gland is derived from the same em- bryonic mesoblastic mass which gives rise to the genital glands ; and that in adults cortical changes in the supra- renals are intimately correlated with reproductive changes, and a general view of the factual basis on which the sugges- tion rests is before us. We may, I think, regard the sugges- tion not only as justified but as revolutionary in comparison with any theory that was scientifically justifiable until re- cently. The following further quotation from Phleps brings the idea into still clearer view : "The unqualified dependence of the nervous system on the epithelial bodies (this last used in the sense of general physi- ological considerations, and only by way of illustration), and the absolutely vital significance of this enables us to see many things in a new light. We learn that many motor, sensory and vasomotor-trophic functions of the central nerv- ous system even up to the highest reflex stations having the most complicated cortical functions, are in constant func- tional cooperation with organs which heretofore have not re- ceived sufficient consideration from this standpoint. The results compel a change of our views concerning the con- stantly dominating position of the nervous system. We may see in many of its activities only the most manifold inter- mediary roUs between glandidar functions which are in the closest relation to metabolism, and the sum total of all re- actions which follow external stimuli.^' ^^ Chemico-Functional Integration 137 Summary of Present State of KnowJedye In This Field Speaking generally, we may say that the trend of all re- sults, experimental and clinical, is unquestionably toward a demonstration of the closest interaction l)etween the entire internal secretory system and both the autonomic and cere- brospinal nervous systems, this interaction affVcting the whole of both the growth and the functioning of the animal organism. But we must remind ourselves again how fragmentary knowledge is in this great realm. Unanswered questions meet one on the ver}'^ threshold of any portion he enters, \^y way of illustration, take the phenomenon of abnormal growth known as acromegaly. This malady is characterized, as tlie name indicates, by a "peculiar non-congenital hypertrophy of the upper and lower extremities and of the head." ~^ Sucli, according to Schafer, is the definition given by Pierre Marie, who first fully described the disease. The main visible symp- toms consist in the enlargement of the bones of the head, hands, feet, chest, etc., especially in their terminal portions. Through such growth the nose and lower jaw, especially the chin, become protrudent. But the whole skeleton is more or less affected, and there is a corresponding over-development of tlie muscles, the affected person becoming abnormally strong. That acromegaly is constantly associated witli an abnormal condition of the hypophysis is recognized by ap- parently all authorities. Whether the abnormality of the gland is a cause or only an accom]^animent of the disease is an open question in the minds of some. However, the view of a large majority is that such a causal relation does exist. "That the acromegalic skeletal growth," says Schiifir, '*is produced by hypertrophy and oversecretion (or ])erverted secretion) of the anterior lobe is highly probable, both as the result of partial extirpation in animals and from the effect of operative removal of the pituitary tumours in man." ^® The 138 The Unity of the Organism particular issue here, it will be noticed, is the vitally im- portant one of what might be called the functional as distinguished from the hereditary cause or at least incitement of growth. In illustration of the importance of understanding the unification among these complex systems, the manifestation of which is in turn dependent upon the organism as a whole, the following from the address by L. F. Barker already re- ferred to, is impressive. "In how far these sudden and violent excitations of the autonomic nervous system which accompany strong emo- tions are due to the intervention of the glands of internal secretion, and in how far they depend upon direct neural conduction from the brain, we are as yet but ill-informed. I need only remind you of the vasodilation of the face in the blush of shame, of the palpitation of the heart in joy, of the stimulation of the sudoriparous glands which precedes the sweat of anxiety, of the stimulation of the vasoconstrictors, the pupil dilators and the pilomotors in the pallor, mydriasis and goose-skin of fright, to illustrate some of these violent autonomic excitations." ^^ The references here, it will be noted, are primarily mani- festations pertaining to the surface, the integumentary parts of the body, and their scope is what especially inter- ests us. Very nearly the whole list of these parts is in- volved, and probably a complete inventory would be still more inclusive. Now notice the range of manifestations at a deeper level that are involved. "The balance maintained normally be- tween the two antagonistic systems the vagal and sympa- thetic autonomic is one of the most interesting of physio- logical phenomena. Think, for example, of the rate of the heart-beat — how constantly it is maintained at a given level in each individual when the body is at rest ; the impulses ar- riving through the vagal system just balance those arriving Chemico-Functional Integration 139 through the sympathetic system, so as to maintain a rate of approximately seventy-two beats per minute. And a similar balance is maintained in other autonomic domains (e.g., the pupils, bronchial musculature, gastric glands, gastro-intes- tinal muscle, sweat glands, bladder muscles, etc.)."'^'^ And Barker tlien calls attention to the extent to which the normal processes of the body depend upon temporary upsets of these equilibria, examples of which are watering of tlie mouth at the smell or sight of food which appeals to the appetite through these senses, the flow of gastric and pan- creatic juices at the proper time, through indirect stimula- tion; the sudden relaxation of the sphincter and contraction of the detrusor of the bladder in micturition ; the violent contractions of all the muscles concerned in parturition in the female, and so on. We may summarize the results of this chapter thus : (1) The researches of recent years on the internal secre- tory sj^stem and its connection with the great subdivisions of the nervous system, and with the blood, muscular, and reproductive systems, have laid a solid foundation for an un- derstanding* of the chemico-functional basis of tlie animal organism's unity. (2) The emotional phase of the psychic life of the ani- mal is proved to be in direct organic connection with tlu.^ basis. From these results there naturally springs the important question: What relation has human consciousness to this same basis .? An attempt to answer this question will be an unavoidable part of our treatment later of the ])sychic in- tegration of the organism. REFERENCE INDEX 1. Luciani II, 13 5. Bayliss 707 2. Carlson and Woelfel 49 6. Bayliss and Starling 325 3. Schiifer (1914) 18 7. Bayliss 706 4. Hertoghe 194 8. Schafer 28 140 The Unity of the Organism 9. Luciani II, ^ 10. Luciani II, 35 11. Schafer 9 12. Schafer 11 13. Aldrich 457 14. Bayliss 721 15. Waller 277 16. Waller 280 17. Waller 281 18. Langley 240 19. Bayliss 484 20. Cannon, W. B.('16) 22 21. Garrison 144 Q'2. Cannon, W. B. ('16) ... 34 23. Garrison 146 24. Cannon, W. B. ('13) ... 372 95. Falta 59 26. Eppinger, et al 214 27. Eppinger, et al 217 28. Schafer 106 29. Schafer 69 30. Garrison 146 Chapter AV.Y THE ORGAMSMAL SIGMFICANCi: OF IIIK INTERNAL SECRETORY SYSIKM TT remains now to consider the real purpose for wliicli -■- the presentation of facts and views on internal secre- tions has been made, namely that of showing critically the significance of this secretory system for the organismal conception. General Iiiahility of Element alls m to Interpret the Phenomena There is perhaps no better way of approaching this part of our task than by noticing the inability of elementalistic biology to deal in a really intelligent and consistent manner with the phenomena in this field. The breakdown of bio-ele- mentalism when confronted with the phenomena of "chemical messengers" nowhere finds more cogent illustration than in the effort to identify internal secretions with the organ- forming substances hypothesized by Sachs and others. Although in what follows the exposure of inconsistency and fallacy will haA^c to be drastic and may seem personal, the truth is it is wholly impersonal in spirit and is directed at a system of bad reasoning born of what might he called a juvenile metaph3^sics of the living world. The objective achievements of Jacques liOcl) and others of the school he represents, in experimental biology, ment the admiration of all lovers of obser^'ational truth. One may be, too, more tolerant of their faults as reasoners 141 142 The Unity of the Organism than he could be but for his recognition of their high service against all the traditional forms of supernaturalism. The real case against the school is, as I see it, two-fold. First, in their zeal to substitute naturalism for supernaturalism they fail to notice that supernaturalism is in its very essence finalistic, and they are led to imagine they have attained, or can attain, natural explanations that fully supplant the old supernatural explanations. This results in the con- version of their supposed naturalism into something which is essentially another kind of supernaturalism. The second part of the case against the school is its abuse of the most common principles of the knowledge-getting processes in ob- jective biology. For the general good of the biological sciences the urgent need of reformation touching both as- pects of the case has led me to examine the particular in- stance of Loeb's treatment of internal secretions at greater length than would otherwise be justifiable. Critique of the View That Internal Secretions are ^^Formative Stuffs" Although Loeb is the only author, so far as I know, who has expressly contended for the identity of internal secre- tions with Sachs' organ-forming substances, the assumption is so accordant with the spirit of elementalism, and Loeb is so typical and eminent a protagonist of this philosophy, that his proposal will probably find many adherents. It is consequently desirable to see what there is in the effort to bring hormones into such a historical setting. The statement of Loeb's Aaews is contained in "The Or- ganism as a Whole from a Ph3^sico-Chemical Viewpoint," 1916. Referring to his espousal twenty-five years ago of Sachs' hypothesis to explain heteromorphosis, he writes : "At that time the idea of the existence of such organ-forming substances was received with some scepticism, but since then Significance of the Internal Secret or ij System 143 so many proofs for their existence have been obtained that the idea is no longer questioned. Such substances are known now under tlie name of 'internal secretions' or 'hormones'; their connection with the theory of Sachs was forgotten witli the introduction of the new nomenclature." ^ A case to which Loeb makes special reference as proof that internal secretions are the same as Sachs' organ-form- ing substances is that of the effect of thyroid on the meta- moi-phosis of the tadpoles of frogs and toads, demonstrated by Gudernatsch. The author's mode of using this case in illustration of his contention is highly instructive. He re- fers to the legless condition of the tadpoles and calls atten- tion to so much of Gudernatsch's results as pertain to these members. Gudernatsch found, Loeb points out, that where- as in the usual course of things the tadpoles live from four months to a year before the legs grow out, by feeding them on thyroid gland these members can be induced to appear at any time. "We must, therefore, draw the conclusion," Loeb says, "that the normal outgrowth of legs in a tadpole is due to the presence in the body of substances similar to the thyroid in their action (it may possibly be thyroid sub- stance) which are either formed in the body or taken up in the food." " When the case is presented in this way and nothing more said about it, it certainly looks considerably as if the thyroid substance or something like it is leg-form- ing substance ; and such an interpretation would be enticing were it really true, as Loeb says, that no other substance seems to have sucli an effect. When, however, one consults the account given by Gudir- natsch himself as to wliat his experiments were and what they established, the whole matter stands in a quite different light. First of all, the fact that in tliese experiments mam- malian thyroid was largely used as food for the tadpoles, thus bringing it to pass that if thyroid substance was specific organ-forming substance, then frogs' legs were produced by 144 The Unity of the Organism mammalian substance, shows at once that there is something badly askew in the theory. So we are incited to examine the facts, and particularly the reasonings, carefully. The following is taken from one of Gudernatsch's papers : "The most striking and at the same time unquestionable re- sults were attained by thyroid feeding. . . . The influence of the thyroid food was such that it stopped any further growth but on the contrary led to an abnormal diminution of the size in the animals treated, while simultaneously it ac- celerated the diff*erentiation of the body immensely and brought it to a premature end." ^ In other words, the effect of thyroid food was to stop the increase in size of the frog's larva and start, almost at once, its transformation into the adult. Now this transformation does not consist merely in the production of legs, but in a whole series of changes, some of which, like leg transformation, are progressive, while others are regressive. For example, one of the re- gressive changes to which Gudernatsch gives particular attention is the resorption of the tail. "Reduction of the body mass (resoi^jDtion of the tail, loss of water, therefore an increasing compactness of the body, etc.)"* more than in normal development, the author says, goes hand in hand with the progressive changes. That is, when the entire series of results of thyroid feeding are considered, and not merely one result picked out arbitrai'ily, then in case we choose to say the thyroid substance is organ-foiTning as regards legs, we should have to say it is organ-destroying as regards tail. Furthermore, if we call the thyroid substance organ- fonning, consistency would compel us to recognize that one and the same substance is not only formative of legs but of numerous other organs and parts, as of the skin, mouth, respiratory and blood systems, all of which undergo, as is well known, progressive changes during metamoi-phosis. Nor is this complex series of morphological changes the while story. Striking and characteristic changes in the habits Significance of the Internal Secretory System 145 of the tadpoles resulted. "Towards the end of metamor- phosis the animals hardly moved about in the water. Tliey were always lying quietly, generally on Huir hacks. When disturbed they would move for a few seconds in a somewhat convulsive manner and tlien drop again to the bottom of the dish, while tadpoles fed on otlier material would swim about for a long time." ^ So mammalian thyroid substance is not only organ-forming for a whole series of frog organs but it is habit-forming for a variety of frog habits ! But Ave must not let the ludicrousness of this veer us away from the reasoning; in the case. Takin"; the facts .,'0 o actually brought out by Gudernatsch, what becomes of the specificity of the substance, which according to Loeb's state- ments was what Sachs hypothesized.^ "Sachs suggested that there must be in each organism as many specific organ-fonn- ing substances as there are organs in the body." ^' The trutli appears to be that thyroid substance in tliis case is organ- forming in much the same sense that water is organ-forming for the leaves, flowers, and fruit in a squash vine, which could not develop without water. Indeed the analogy suggested goes further than appears at first sight. As everybody knows, the effect on young plants of a scant water supply is to stunt the plant as to size and to hasten its blossoming and fruiting. That is, an under-supply of water has an effect on immature plants similar to that of an over-su])ply of thvroid substance on immature frogs, namelv that of re- tarding growth and hastening metam()r|)hosis. The total effect in each case is systemic. In other words, tiie real significance of the instance used by I.oeb is just the opjiosite of his interpretation of it. Thyroid substance is oryau- forming only through being organism-transforming. Full justification of this way of interpreting the ])art in development played by thyroid substance is furnished by the recent studies of 15. ^\. Allen. This investigator has, like Gudernatsch, experimented with frog larva\ lie has, how- 146 The U7iity of the Organism ever, supplemented Gudernatsch's work by depriving the larvas of thyroid altogether instead of giving them an extra allowance through feeding. Allen extirpates the entire em- bryonic thyroid from tadpoles long before any indications of metamorphosis appear. What he finds of special impor- tance for the present discussion is contained in the follow- ing; "While Gudernatsch showed that thyroid feeding acceler- ates development, this work shows that the total absence of the thyroid gland produces complete cessation of somatic differentiation at a certain stage but does not hinder con- tinued o-rowth in size." ^ The first part of this statement taken alone might be looked upon as confirmatory of the "formative stuff" theory of thyroid substance. But the phrase "at a certain stage" implies, as Allen's paper as a whole conclusively shows, that the exact opposite of such a conception is alone tenable. What actually happens, Allen brings to light, is that in spite of the complete absence of thyroid substance trans- formation of the larva is begun but is not carried through. That is, the organs and parts of the adult frog are laid down but (with the exception of the reproductive glands) are not completed. "It is evident," Allen says, "that the thyroid gland is in no wise essential to the earlier phases of development, but that at a certain definite stage, further development of the soma is dependent upon it." '^ It should be mentioned that Allen makes a rather special point of the accordance of his results with those of Gudernatsch. If the greatly hastened and modified metamorphosis of the frog tadpole observed by Gudernatsch is inducible by no other means than by thyroid substance (which while pos- sible is not at all certain), then is the substance causal in the important sense of being not only competent but in- dispensable. But even so it falls far short of being a com- plete causal explanation of the phenomena under contempla- Significance of the Internal Secretory System 147 tion, as Allen's results directly prove. A defect in Loeb's reasoning is liis ignoring the truth that thyroid substance lacks in the case cited tlie prime attri})ute of a sufficient cause, namely full competency. The actual substance which enters into the new legs, and as far as that goes, into the other new parts, is probably provided very little, if at all, by the specific substance or hormone of the thyroid. The causal role played is the relatively humble one of excitor or stimulator to an activity not essentially new but only exceptional as to time. Of course Loeb does not need to be told that hormones incite growth rather than provide the substance itself out of which the organs and parts are built. Indeed portions of his account of this very case show positively that he is aware of this. We read : "Thus we see that the mesenchyme cells giving rise to legs may lie dormant for months or a year but will grow out when a certain type of substances, e.g., thyroid, circulates in the blood. There may exist an analogy between the activ- ating effect of the thyroid substance and the activating effect of the spermatozoon or butyric acid (or other par- thenogenetic agencies) upon the Qgg.'^'' ^ This suggestion of analogy between the action of thyroid secretion and "butyric acid (or other parthcnogenetic agen- cies)" is well taken. The resemblance between the two agencies, as judged by their effects on development, is cer- tainly rather close. Very well ; would Loeb, then, call bu- tyric acid organ-forming substance, and identify it with the "formative stuff" of Sachs .'^ Certainly any substance which will rouse the latent developmental cai)acitics of an Qgg into activity is in a minor sense formative, especially if these capacities are wholly unable to start without some such agency. But since butyric acid, or some one of tlie other dozens or scores of parthcnogenetic agencies, may activate the eggs of many, many species of animals; and since the eggs of many, many species may be ai^tivated by any one of 148 The Unity of the Organism scores of such agencies, what about the specificity of the formative substances which Loeb himself expressly says was A^rt of Sachs' conceptions? jj^gain, how reconcile the contention that thyroid sub- ^^ts^e or something like it is organ-forming for the legs olM- ^SWpole witli the statement quoted a few paragraphs bac^aljjlit mesenchyme cells which give rise to legs? The ^Md^jmy steal and Logical Weakness of the View Obviously Loeb's treatment of this subject contains irre- conciliable contradictions. Is it then worthless? My answer is, no, not by any means. But how comes it that a scien- tist of his great experience and merited distinction can run into such self-destroying speculations and statements, seem- ingly without rational discomfort to either himself or others of the school which he represents? The answer takes us back to some of the most funda- mental issues between the elementalist and organismal stand- points, and though not requiring us to palliate in any degree such offenses against scientific reasoning, it partly explains how tolerance for such oflTenses is begotten, and discovers a nucleus of genuine merit in Loeb's position. Bringing the matter to as basal a statement as possible, what we find is that this whole book on the Organism as a Whole is written on the theory that the only alternative to the assumption of supernaturalism is materialism. Instead of supernatural forces of some sort (Platonic Ideas, entelechies, psychoids, "supergenes") for explaining the organism when regarded as alive and whole, his assumption is that material elements as known to us in inorganic nature are the sufl[icient causal explanation of organic phenomena. Were this theory correct — were it true that the "vital principle" must either be conceived as supernatural or tliat the inorganic elements taken by themselves are competent Significance of the Internal Secretory Sij stent Wd to produce organisms, then it would be impossible for biol- ogy to do much better in its reasoning and general attitude than Loeb and other elementalists do when they undertake to construct a philosophy of organisms. I agree wliole- heartedly that all supernaturalism, no matter what nomen- clatorial garb it takes on, must be repudiated by the sciences of organic beings. Ideas, or psyclioids, or entelechies, or "principles" of any kind conceived as independent of, or even separable from, sensible objects are quite as repugnant to me, an organismalist, as they are to any elementalist. The essence of my contention is that the natural substitute for these imponderable things are the living, individual organ- isms themselves, and not the particles of which they are com- posed. Each and every individual organism is a natural reality by exactly the same criteria that the atoms, mole- cules, cells and tissues of which it is composed are natural realities. And since each individual is to some extent differ- ent from every other, and maintains its individuality in full possession of these differences, by its power of transforming foreign substance into its own substance, it is ultimate both as to structure and as to causal power in as deep and literal a sense as the material particles of which it is composed are ultimate. Loeb's considerable attention to the views of Claude Ber- nard is fortunate for us, since it affords a chance to show from still another angle the inevitable breakdown of ele- mentalist reasoning when it is brought face to face with or- ganic phenomena as actual nature presents them to tiie modern student. Loeb calls attention, pro})erly, to the fact that one of the things on which Bernard ]ihu'ed special em- phasis, as Bichat before him had done, is the organizing syn- theses which go on in the living being. The real advance, it seems to me, which Bernard made over any of his ])re{leces- sors, was the positiveness of his rejection of a vital force as something supernatural— as something, using hi-; own 150 The Unity of the Organism words, "under the government of a special principle, a pecu- liar power what name soever be given it, whether soul, or archeon, or psyche, or plastic intermediary, or guiding spirit, or vital force, or vital properties";^ and his rejec- tion of these conceptions because of his recognizing that the unitariness of the organism removes the necessity for as- suming any such extraneous principle. "When we say," Bernard writes, "that life is a guiding idea, or the evolu- tive force of the being, we merely express the thought of a unity in the succession of all the morphological and chemical changes effected by the germ, from the beginning to the end of life. Our mind grasps that unity as a conception it cannot escape. . . ." ^^ Up to this point the position held by Bernard is entirely satisfactory for the organismal conception as I am trying to develop it, and is, according to my view, unassailable. But the unquoted part of the last sentence contains a state- ment which reveals Bernard on a by-road leading away from the promised land toward which he w^as headed as long as he was speaking in terms of biology proper. The rest of tlie sentence follows : "and explains it as 'a force' ; but the mis- take is in supposing that this metaphysical force acts after the manner of a physiological force." ^^ Stated in a nut- shell, the by-road which Bernard is entering here is that of a kind of separatedness, but inevitable concomitance, or paral- lelism between the phenomenal and neumonal worlds which, according to the views upheld in this volume, does not exist. "We need here," Bernard says, "to draw a distinction be- tween the metaphysical world and the phenomenal physical world, which serves as its basis, but which can borrow noth- ing from it." This Leibnitzian theory, according to which "everything takes place in the soul as though there were no body, and in the body everything takes place as thougli there were no soul," Bernard says science "recognizes and adopts in our day." But in our day, this year nineteen Significance of the Internal Secretory System 151 hundred and eighteen, science, at least so much of it as speaks through tliis vohnne, tliou^li understanding fully what this dualist theory is, rejects it. It denies that things take place in the soul as though tlure were no hody; and that things take place in the body as though tliere were no soul. On the contrary it affirms that what in rather un- critical language we call "the hody" and "tlie soul" are in the most intimate and indissoluble connection with and de- pendence upon each other, and together constitute "the Orcranism." o The Form of Metaphysical Absolutism Involved A full, systematic justification of this position is beyond the province of this volume; and in this chapter we are con- cerned solely with the "body," the strictly morphological and physiological aspect of the subject. Nevertheless, this much of contact with the "soul" aspect was unavoidable for the reason that Bernard and also Locb have run into it in such fashion as to color deeply their discussions and out- look. This coloring is the more unfortunate and the more insistent in requiring attention from the fact tliat the au- thors, especially Loeb, are apparently unaware of such coloring. For example, Loeb writes on the first page of his book, after saying that the atomistic theory of matter and electricity are now in all probability on a "permanent basis": "This permits us to state as an ultimate aim of the physical sciences the visualization of all phenomena in tenns of groupings and displacements of ultimate particles, and since there is no discontinuity between the matter consti- tuting the living and non-living world the goal of biology can be expressed in the same way." Statements like this, many of which can easily he ([uoled from Loeb's writings, leave no question about his meta- physical affinities. The conception of "ultimate particles" 152 The Unity of the Organism as explanation of all phenomena, is exactly what I mean by elementalist absolutism. Confusion of Theory of Organisms and Theory of the Knowledge of Organisms Although the thoroughgoing metaphysical character of these statements is evidenced by the finalism which crops out at several points, this is not the aspect of the matter which chiefly interests us here. Rather what we are con- cerned with is the fact that affirmations about the "aim of the physical sciences" and the "goal of biology" do not belong, properly speaking, to the provinces of physical science and biology at all, but to quite a different science, namely that which deals with the nature of knowledge itself. The "physical sciences" are the vast accumulation of man's positive knowledge, theories, hypotheses, and so forth, about physical nature; they certainly are not physical nature it- self. Consequently a statement of the character and aims of that knowledge is not a statement about the phenomena to which the knowledge pertains. And the same reasoning applies to the affirmation about the goal of biology. All this is only another way of saying what Loeb him- self virtually tells us, namely that his entire discussion of the organism as a whole is made from the standpoint of one particular theory of the ultimate nature of living beings, that theory being the mechanistic. Recall the complete title of the book The Organism as a Whole From fhe Physico- Chemical Viewpoint. To treat the subject from this view- point is of course perfectly legitimate. When, however, the assumption is made that such a treatment is the only really legitimate one because it rests on idtimate truth, then sound science is bound to protest, chiefly because of the obvious biological inadequacy, and at some points, perversion and contradiction displayed in the treatment. Significcmce of the Internal Secretory System 153 This brings us back to the way internal secretions are dealt with bj Loeb. His failure to (Hstlnguisli between tlie two very distinct fields of theory above indicated, namely theories about the phenomena of living beings, and theories about knowledge of these piienomcna, largely explains the defects of the theoretical parts of his work. And we are now in position to give our criticism greater expllcitness. Consider for example in tlie light of what has just been said about confusion relative to kinds of theory, the irreconcil- able statements, cited on an earlier page, that the mesen- chyme cells give rise to the legs of the tadpole, and that thyroid substance is organ-forming substance for the legs. Stated briefly the case seems to be thus : Loeb recognizes, as every one must, that internal secretions constitute a physico- chemical agency for bringing about that harmonious de- velopment and functioning so characteristic of the organ- ism. But this harmony is one of the very things which has seemed to some biologists inexplicable w^thcxit the assum]>- tion of supernatural influences of some sort; hence Driesch's attempt to modernize the ancient entelechy. But since in- ternal secretions play the role that entelechies are sup})osed to play, namely that of establishing and maintaining the unity and equilibrium of the organism, the need for ente- lechies no longer exists ; at least, this would be so for all persons who do not contend that "ultimate explanation" is the "goal of science." To those who hold these absolutist beliefs as to the power and aims of science three favorite courses are open and are followed by different representatives of the school, depend- ing on the taste, training and outlook of the person. One course consists in pointing out, taking an illustrative case, that internal secretions, being only contributing causes, do not constitute an ultimate ex])lanation, so tliat entelechies or something similar arc as necessary as l)i'f()rc. 'I'his would be the course followed by the vitalistic wing of the ahsolu- 154 The Unity of the Orgcmism tist school. For them internal secretions would be, in so far as they contribute to the harmony of the organism, merely agencies produced and used by supernatural causes. Another course, and perhaps the one most frequented by elementalists, would be to contend that internal secretions are sufficient as a causal explanation of organic unity to make the entelechy or any similar notion quite superfluous, even though these substances are far from a complete ex- planation. The reasoning of this group of elementalists as to this situation is substantially as follows : although in- ternal secretions fall far short of fully explaining organic unity and harmony, the action of these being merely that of incitors and inhibitors, they are yet genuinely causal, genuinely physico-chemical and so are on the road toward complete explanation of the phenomena. All that is nec- essary consequently, is to believe that still further advance in the same direction will reach finallv a full elementalistic explanation ; that is, an explanation which will have no need of either supernatural elements or the organism as a whole. The attitude of this large class is one primarily of faith rather than of reliance on positive knowledge ; they are inspired more by what they believe they will do in the future than by what they actually have done. They are preemi- nently men of promises. Although their achievements in experimental science are indeed large, the results reached by them are prized more on account of what they are believed to augur for the future than for their present meaning and worth. Then, finally, there is the group of elementalistic absolu- tists, of whom the author of The Organism as a Whole from the Physic o-Chemical Viewpoint is one of the most eminent in our day, w^ho, as we have pointed out, by confusing theo- ries about objective phenomena witli theories about the knowledge of such phenomena, are led to affirm that such phenomena as the unity of the organism are fully explained Significance of the Internal Secretory System 155 by internal secretions, Avhcn as a matter of fact tliey are only partly explained thus. The surprising tiling about the confusion of this group is that wholly irreconcilable positions are held with ini[)uii- ity, such for instance as those according to which thyroid substance is held to be the organ-forming substance of frogs' legs in one part of a discussion, and mesenchyme cells are acknowledged to be of this nature in another part. Tlic contradiction is, to be sure, often of such character as easily to escape the uncritical reader; but as to the au- thors of such contradictions no other explanation seems possible than that of wrong habits of scientific thought be- gotten of untenable a priori conceptions. For example, a hasty reading of the discussion under review might lead one to suppose that thyroid substance is not, after all, regarded by Loeb as anything more than one contributing cause of frogs' legs, mesenchyme cells being recognized as another cause. Close attention to the text does not, however, war- rant this generous interpretation of the author's position. Going back to his espousal of the theory of Sachs and other botanists as to organ-forming substances, we read : "Specific shoot-producing substances are carried to the apex, while specific root-producing substances are carried to the base of a plant. When a piece is cut from a branch of willow the root-forming: substances must continue to flow to the basal end of the piece, and since tlieir further progress is blocked there they induce the formation of roots at the basal end." 1^ If this means anything it means that the shoots and roots are actually built up by material carried about in the wil- low branch. There is nothing in the language tliat can he interpreted as meaning that shoot-and-root-forming sub- stances are mere stimulators of some other substances which become the actual shoots and roots. Yet it is witli forma- tive substances of this sort that Loeb in some parts of 156 The Unity of the Organism his discussion explicitly identifies internal secretions. "At that time the idea of the existence of such specific organ- forming substances was received with some skepticism. . . . Such substances are known now under the name 'internal secretions' or 'hormones' ; their connection with the theory of Sachs was forgotten with new nomenclature." ^ Then follows the reference to the tadpole legs ; so that were consis- tency really a jewel to the author, he could not escape mean- ing that the substance of the legs was actually derived di- rectly from the particular internal secretion in question, in this case thyroid substance; and the later statement about the formation of legs from dormant mesenchyme cells through the mere activating effect of thyroid substance is by implication contradicted. This brings up again a matter about the interpretation of development which we have dwelt upon in several other connections, that of protest against rejecting the indubi- table evidence of the senses in favor of a priori conceptions. The crucial question in the present case is this : which is the more fundamentally organ-forming substance for frogs' legs, the mesenchyme cells which "though giving rise to legs may lie dormant for months," or the thyroid substance which may stimulate these cells into premature activity? While Loeb's discussion does not raise this question definitely, the implication is unescapable that thyroid substance is for him the more fundamental. What else is the meaning of the contention that this substance is organ-forming while no- where do we find the mesenchyme cells so designated? Yet the observational evidence is that the production of legs is accomplished through the transformation of mesenchyme and other cells which in the larva are not leg-substance, but in the adult are leg-substance. Hence it follows that so far as actual observation is concerned the mesench^^matous and other larval substances are more entitled to be called organ- forming than is the thyroid substance. Significance of the Internal Secretory System 157 An Illustration of Neglect of Fact By ElevientaUst Theory Tliesc reflections lead to a still deeper level of the inherent faultiness of elemcntalistic absolutism in biolo'^y, the toler- ance which it engenders for ignoring relevant facts; or stated otherwise, of arbitrarily selecting from a great com- plex of facts just those which suit the argument, and dis- regarding all the others. For example, recall Loeb's ref- erence to precocious leg-production in frog tadpoles as though the effect of thyroid feeding stood alone rather than as one among a great concatenation of effects, some con- structive and some destructive, this complex of phenomena constituting the metamorphosis of the young into the adult. Loeb's use of Gudernatsch's results amounts to a positive obscuration for the reader of what these important experi- ments really teach. Only by the culling of facts to suit the argument and the use of certain words and phrases, as "influence," "responsible for," and so on, with equivocal meanings, can these results be made to support the conten- tion that thyroid substance is specific organ-forming sub- stance for frogs' legs. The patent fact is that certain mesenchyme and other cells of the larva are organ-forming for legs, and there is no straightforward way of talking about the causes of the transformation of a given grou]) of more or less undifferentiated tadpole cells into the much enlarged and highly differentiated group called a leg, with- out recognizing the whole organism as causal of the ])ar- ticular transformation. Probably no set of discoveries con- cerning the development of the individual has ever Ix^en made which so objectifies the means employed by the whole in producing and correlating its constituent parts as those on internal secretions ; and not the least significant fact is that these substances are themselves produced by tlie or- ganism. Even were Loeb's contention valid that thvroid substance 158 The Unit?/ of the Organism is specific organ-forming substance, the indubitable fact that in normal development tliis substance is itself a product of the organism's activities, throws it into a very subordinate place as a cause of development. Tlie truth is, the main upshot of the effort to explain ontogeny on elementalistic principles amounts to an effort to avoid recognizing the most positive and definite entity in the whole situation, namely the organism taken alive, normal and untampered with. A Peculiar ElementaUst Objection to the Organic Whole We now come to the last point to be noticed in connec- tion with the elementalist attempt to deal with internal se- cretions as related to the organism as a whole. Instancing the familiar way in which a particular part of a flat-worm will give rise to a new head after being cut away from tlie original animal, when no head would have been formed at this place had not the animal been cut, Loeb writes : "How does the 'whole' suppress all this formative power in the part be- fore the latter is isolated? It almost seems as if the isola- tion itself were the emancipation of the part from the tyr- anny of the whole. The explanation of this tyranny or of the correlation of the parts in the whole is to be found, how- ever, in a different influence." ^^ Then follows the statement previously quoted about the specific organ-forming substances of Sachs and other bot- anists, and the assumed identity of these with internal se- cretions. Without raising the question concerning the evidence for the assumption that the production of a flat-worm's head as indicated is dependent upon internal secretions, let us consider a moment the interesting conception thrown into the treatment that the whole flat-worm tyrannizes over its parts. Why this.'^ Is it "mere rhetoric".'^ We are not per- mitted to judge it thus, for no one has pronounced against Significance of the Internal Secretory System 159 this sort of thing in science more frequently than Loeb. The conception that the "whole" exercises a "tyranny" over the parts we must accept as being seriously scientific with Loeb. Well then, since tyranny is "absolute power arbitrarily or unjustl}^ administered," according to the dictionary, it is certainly interesting to an organismalist to find so eminent an elementalist acknowledging the organism as a whole to be truly causal relative to its parts — for it is hardly conceiv- able that even the extreme pliability of elementalist practice as regards the definition of words would venture to hold the absolute power which constitutes tyranny to be without causal efficiency. Power thus potent but which could cause nothing, not even the destruction of the parts (for surely the tyranny of the whole does not destroy the parts), would be too queer a conception for anybody to father deliber- ately. But the most interesting thing about this idea of the "tyranny" of the whole over the parts remains to be no- ticed. T3^ranny is not merely absolute power; it is such power exercised unjustly or "in a manner contrary to law or justice." Here we come, I think, to about the last ditch of the ele- mentalist position. On what ground does one conceive the power exercised by the whole organism over its parts, to be contrary to law or justice. According to what legisla- ture or court is there a law of the parts of an organism more just than the law of the whole? None whatever in nature, it must I think, be admitted. The only ground for the ele- mentalist's pronouncement, that the wliole acts tyrannously toward the parts, that it acts in a manner "contrary to law or justice" is in the mind of the yerson who makes the pro- nouncement. The truth is — and it is of great importance since its influence reaches far beyond the confines of scientific tech- nicalities — any scientist, especially any biologist, who is 160 The Unity of the Organism through and through an elementalist, is necessarily a protes- tant against all law except the law of elements. The scientific elementalist is inevitably anarchistic toward all the most common, most objective, structures and laws of nature. His faith is in the laws of the obscure or invisible world and against those of the everywhere visible world. Atoms are more real to his mind than are lands and waters, plants and animals. REFERENCE INDEX 1. Loeb ('16) 155 2. Loeb ('16) 156 3. Gudernatsch 475 4. Gudernatsch 476 5. Gudernatsch 476 6. Loeb ('16) 159 7. Allen ('18) 515 8. Loeb ('16) 156 9. Bernard 516 10. Bernard 519 11. Loeb ('16) 154 12. Loeb ('16) 154 Apjirvh AU jKorri Chapter XX NEURAL INTEGRATION Neural and Not Fsycliical Phenomena the Subject of ThU Chapter THE fact should be firmly fixed in mind at the outset that in this chapter we have nothing to do with tlic organism's consciousness and volition. We are to deal with the nervous system purely on the basis of its physical activi- ties. Whether or not consciousness or something of the es- sential nature of it appertains to part or all of the activities to be treated we do not have to decide, so far as this discus- sion is concerned. Our task here is to be strictly anatomical and physiological, and not at all psychological. Distinction Between Developmental and Functional Integration The discussion may be opened by calling attention again to a matter noticed incidentally in the last chapter, namely the relative parts played by internal secretions and the ner- vous mechanism in integrating the developing organism on the one hand, and the functioning organism on the otiier. We saw that the role of internal secretions in preserving developmental equilibrium in the individual is so conspicu- ous as to throw the strictly ])hysio-logical role of tlie sub- stances somewhat into the background. Nevertheless as evi- dence, particularly clinical evidence, lias made clear, tlieir part in functional equilibrium is far-reaching. 101 162 The Unity of the Organism We must now point out specifically what appeared only incidentally in the previous discussion, namely, that the integrative action of hormones and of the nervous system are to a considerable extent the reverse of each other as regards their relation to development and to adult func- tion. That is, while harmones are, perhaps, more impor- tant in development and become relatively less significant with the advancing age of the individual, the nei-vous sys- tem plays a minor part in integrating the developmental processes but becomes of supreme importance in this way for the functioning of the adult. Or, stating the generali- zation in another way, integration of the organism is ac- complished by chemical means chiefly, and by neural means little or not at all, during early life, and by neural means chiefly and by chemical means secondarily in later life. One can hardly fail to see, in a general way, the bearing of this on the familiar truth that the life of the individual among the higher animals, man especially, is successively vegetal, animal, emotional, and finally rational and intel- lectual in its dominant characteristics, with the successive stages of earlier and later childhood, youth, and earlier and later maturity. The Author's Indebtedness to Sherrington's Work My dependence upon Sherrington's work in this field will be so great as to make it impossible to acknowledge it at every point. I therefore make at the outset the general statement that a large part of my discussion consists of a re-wording and rearranging of facts and ideas contained in this physiologist's important book, The Integrative Action of the Nervous System. But while my chief reliance here is on Sherrington's work, the writings of Cannon and his collaborators have been the most important source of what I have to say about tlie autonomic nervous system. Can- \ Neural Integration 103 non's recent book, Bodily Changes in Pain, Hunger, Fear and Rage, has been especially drawn upon. The Fund amen tality of Cellidar Integration in the Reflex Arc In no department of pliysiolog'y do cells keep themselves more persistentl}'^ in the attention of the student than in tlie physiology of the nervous system. But likewise nowhere is the fundamental dependence of cells on other cells more clearly seen ; for -while, speaking from the standpoint of general functions, cells may be looked upon as individual units, when it comes to the study of nerve cells as such, that is, as constituents of the functioning nervous system, the individual cell is found to be no longer the basal unit. Viewed thus the reflex-arc and not the individual cell is the unit. The distinction thus indicated is important from the or- ganismal standpoint and must be considered a little more fully. The general functions of cells to which reference i& made above are those common to all cells, even those of the tissues of fully differentiated multicellular animals. No matter what tissue be under consideration, muscle, gland, epithelial or what not, so long as it is truly living, each and every cell assimilates, breathes, excretes, and carries on all the metabolic processes. Thus far each cell is an indepen- dent unit in a high degree. Now while all tissue cells, using the term tissue in its common histological sense, have a rela- tional or integrational function in addition to these indi- vidual functions, it is in the nervous system that this inte- grative aspect of cell life is most positive and definable. The reflex-arc, as the unit of the nervous svstem, is itself a combination of three indispensable })arts or elements: tlie receptor, the conductor and the effector. Ty})ically these structures contain at least four cells, one for the receptor, 164 The Unity of the Organism two for the conductor, and one for" the effector. An illus- tration would be a reflex-arc consisting of a tactile cell of a touch organ, the two cells constituting the conducting path, and an effector cell in a muscle. A point of special interest in connection with such an arc is that the dependence of the parts on one another is such, in the highest develop- ment of the arc, that the specific action of each part is dependent on the specific and connected action of the other parts. "The optic nerve itself," to quote Sherrington, "is unable to enter into a heightened phase of its own specific activity on the application of light. Initiation of nervous activity by light is the exclusive (in this instance) function of cells in the retina, retinal receptors." ^ And of course without brain cells as effectors for vision the specific activi- ties of receptors and conductors would be impossible. Not only would an optic nerve fiber's conducting ability be useless without a retinal cell on the one hand and a brain cell on the other, but the very conductive act itself would not be fully performed. This specific dependence, as it might be called, of the parts of a reflex-arc is so significant that another example may be profitably noticed. A striking one is afforded by the effects of the passage of gall stones through the gall ducts, instanced by Sherrington, partly on the basis of his own studies. The excruciating pains associated with this malady are due to the distention of the wall of the gall duct by the passage through it of the mineralized organic con- cretions which constitute the gall stones. Tlie point in this for us is the fact that though the stimulus which pro- duces the pain is mechanical and acts upon the wall of the duct, this stimulus is so peculiar that other sorts of me- chanical stimuli of the same tissue, even to cutting and wounding, give no sense of pain. Though the duct may be cut without causing pain, pain may be produced by injecting the duct to distention with neutral fluid. "Marked Neural Integration 1()5 reflex effects can be excited [by fluid 1 from the very or£rans the cutting and wounding of which remains witliout ett'ect." ^ The reflex mechanism inyolyed is adjusted to respond only to a stimulus of a special kind. In tliis it is comparable to the optical mechanism referred to aboye. These illustrations show something of the general nature of the reflex-arc as an integrated structure. But we want to know something about the part contributed by the difl*erent constituents of the arc to this nature. The spe- cific office of sense organs yiewed as the receptor members of the arcs will first engage attention. "The main function of the receptor is therefore to lower the threshold of excit- ahility of the arc for one kind of stimulus, and to heighten it for all others.'^ ^ This principle is so important that we must allow no yagueness as to its meaning. It means that while more than one sort of stimulus may put a particular sense apparatus into operation, there is one and only one kind, namely, that to which the sense organ is naturally subject, that elicits the reflex in its normal or type expres- sion. A sense organ may be looked upon as a group of receptors attuned to a special stimulus, as contrasted with that of the general stimuli to which an organism is always subject by being always in contact with its enyironment. In illustration Sherrington instances the fact that the threshold for the touch-sensation is lower for a mechanical stimulus than for an electrical stimulus. Haying regard to the whole lot of reflex-arcs of the body, we may say that the different sense organs constitute mechanisms of selective excitability/ for the different stimuli, each organ })elng so adapted to its natural stimulus that it responds to this better than to any other. This reference to the sense or- gans as adaptive makes it desirable to notice the fact that, according to Sherrington, electricity is neyer an ade(ju-ested to Loch the idea of "cliain reHexes," a conception of special interest from our stand- point. That the segmental mode of functioning of the vertebrate nerve axis is not limited to the lower portion of the great vertebrate phylum is, as Loeb points out, sho\v?i bv such investigations as those of Goltz, and of (ioltz and l^wald on the dog. These are given so fully in the larger text-books of physiology and are thereby so readily accessible to all specially interested in the subject, that a very brief presen- tation will suffice. Two main groups of reflex centers in the ner\e cord are made out, the cervico-thoracic and the lumbo-sacral. The first group contains the center for movements of the an- terior limbs, for res]:)iratory movements, for acceleration of heart action, for dilation of the pupil of the eye, and for several other activities at the anterior end of the body. The lumbo-sacral group contains the center of movements for the posterior limbs, for control of the anal sphincter, the activities of the generative organs, and several other jiarts. The existence of such centers in the dog's cord was proved by section of the cord at different levels under the most careful operative conditions. Had the investigation st()j)ped with experiments of this sort the facts brought out might have been interpreted as confirmatory of the "seat'' notion of a nerve center. When, however, it was discovered that a dofi- from which most of the cord is removed nuiv live for many months in a good state of health, all the vegetative functions being carried on almost typically, it became clear that the various centers of the cord are not the seats of life activities in any such fundamental sense as was earlier 198 The Unity of the Organism supposed. For one thing the results seemed to show that the sym- pathetic nervous system shares with the central system more profoundly than had been known before, in determin- ing life processes. The conclusions which flow with apparent certainty from the observations are well summed up in the following: "Un- doubtedly all such activities [of visceral life] may subsist and function in a comparatively normal fashion after re- moval of all spinal influence. The office of the spinal sys- tem in regard to the visceral life seems to consist in en- dowing these functions with greater energy, and in con- ferring greater stability and more solid equilibrium on the general constitution of the animal." ^^ The reader will hardly fail to recall, on reading this state- ment about the function of the mammalian spinal cord, Loeb's statement, quoted some pages back, about the nor- malizing function of the Nereis brain. "Stabilizing" the dog's function means much the same as "normalizing" the annelid's functions. Nor should the reader neglect to notice that he might substitute the word "integratedness" for "equilibrium" in the quotation without change in the es- sential meaning of the sentence. Critique of the Elementalist Attempt to Interpret Tropistic and Segmental Theories of the Function of the Nervous System We now return to the central point of the present sub- topic, namely that of what a genuine bio-elementalist is able to do when confronted by the facts in possession of modern physiology bearing on the tropistic and segmental theories of the nervous system. First we are compelled by the evidence to recognize the general soundness of the doctrines. Second, we recognize Implications of the Theories of Xenr Action ID!) tluit probably no biologist has dcalf witli tlu- coniij)! ioii more coniprchcnsively and illuniiiiatiii/)i'ct of serious questioning. "The dog is what lias intervened be- tween the chemical simples and the reflex." That is what common experience nmst answer and will unhesitatingly answer once it recovers from its surprise at being (jues- tioned on a subject so open and daylight clear. But then science comes forward with its criticism of this common-sense answer. There is no gainsaying, it admits, the truth of the naive answer thus given. Ihit this answer, science says, is a mere truism. It leaves the case just where it was before science began its analysis, so is worthless for scientific purposes, however useful it may be for ordinary purposes. This rejoinder by science nuist be looked into caicfully; otherwise its weakness will be missed. It must be exacted of science that she show more explicitly than she has what she means by explaining the dog's scratch-reflex by refer- ring it to the physico-chemical elements at the l)asis of the act. Let us, we must insist, hear you express a dog's scratch-reflex in the terms of oxygen, carbon, et cetera. That such expression is possible is freely granted. Hut how can it be done? That is a key (piestion. It can l>e done in one and only one way, namely by adding to the attributes, that is, to the "terms" which inorganic chemistry recoirnizes in the chemical ileim-iits concenied, iust those attributes and terms which the dog's scratch-reflex requires in order that the elements may explain the reflex. We can say that besides the si>ccific gravity, combining weight, and 204 The Unity of the Organism other well-known attributes of the elements, they possess dog's-scratch-reflex attributes. But, the name thus sug- gested for the newly discovered attributes being cumber- some, we may devise for them some term more simple and convenient — for example, do-sca-re-x, doscarex. In virtue, then, of the doscarecious powers of oxygen, carbon, and so forth (the fact that these powers can only be assigned in the lump and not distributively to the several elements should not be lost sight of though it may be neg- lected for the present argument), a complete physico-chem- ical explanation of the phenomenon under consideration is reached. Does this discussion advance the interpretation, the under- standing of biological phenomena beyond the familiar sar- casm about explaining drug-induced sleep as due to a dor- mitive principle of the drug? Yes, I maintain, it does, because in place of a "principle" attached to no particular drug but to any sleep-producing substance, the doscarecious powers recognized by us are definitely assigned to the chem- ical elements known to be the sole constituents of organ- isms. The new powers take their place perfectly, definitely and positively among the other attributes of the elements, the assignment being based on the solid ground of analyses, laboratory and other, made through years of scientific re- search. But an exceedingly important point which comes in sight here is that though these doscarecious powers are proved to be real ones, they are latent and wholly unknown to inorganic chemistry for tlie reason that they never mani- fest themselves under any other combination of things than just that which in its totality Zoology has named dog. A dog, and a dog only, is able to cause oxygen, carbon and the other elements to reveal these particular scratch-reflex powers. The dog comes in as a sine qua non to the pro- duction of, and hence to the causal explanation of, the particular group of activities under consideration. We Implications of the Theories of Nerve iction 205 liave no evidence that the chemical elements oiJcratliiL'' them- selves can actualize their own latent doscarecious powers. The reader will hardly fail to connect what we are say- ing with the familiar phenomena of the assimilation hv organisms of nutrient suhstances. All our aririiinciit really does to the usual conce])tion of this pheiiomiMoii is to focus attention upon the fundamental im|)ortance of the iml'n'idu/tl organism as a factor, as a cause, of the chemical transfor- mations wrought in the nutrient substances. The insnf ficiency of statement of the assimilative, oi- anabolic, or synthetic aspect of the metabolic cycle in the organism, lies in its failure to bring out clearly enouirh the Indubitable fact that the final results are innumerable activities and sub- stances which pertain solely to the living, normal indiridual — which are strictly personal and private, as one may say. The current mode of expression according to which the assimilative syntheses take place in the organism is (juite misleading in that it permits or even encourages a concep- tion that the syntheses have a measure of detachment from, and independence of, the life of the organism as a working unit, which as a matter of fact they do not have. Again, the usual statement that the syntheses result in orga?iic sub- stances of more complex, higher make-up is inadetjuate in that it diverts attention from the fact that these new sub- stances belong to, are fundamentally ])ai"t and parcel of trie orxj-anism. Thev are not "any old organic substances** but are exactly those substances necessary to maintain the nor- mal life of the ])articular individual organism. IKiui- de- spite the indubitable fact that the final results an- reached by w^ay of innumerable |)urely pliyslcal and chemical ojH'ra- ations, the organism itself, acting as an integer no niattir how complex, is always to the fore as a controlling, donn- nating factor. 206 The Unity of the Organism The Bearing of This Critique on "Analysis" in Biological Reasoning The considerations thus briefly set forth lead to certain still more general ideas of the utmost importance. The natural entities to which we apply the descriptive terms living and organic are specially distinguished by the chem- ical and physical syntheses which they accomplish by virtue of their inherent constitution. So as concerns the most characteristic of these syntheses, especially the chemical ones, they are to a very considerable and fundamental ex- tent definitive of the organic individual, species, genus, and so on, of taxonomic biology. This is equivalent to saying that the synthetic operations regarded each by itself ter- minate in results which are in large measure unique and so unforeseeable from anything we know about the original elements as such; that is, before they have actually been subjected to the particular synthetic transformations under consideration. And this again is equivalent to saying that synthesis — transformatory synthetic processes and products— is more distinctive of living beings than are analytic products and processes. Finally, it follows from these facts about the synthetic nature of organisms, and from the established principles of thought, that analysis alone is incapable of intei'preting, of understanding organic beings. No natural object which in its nature is more distinctivel}^ synthetic than analytic can be understood by knowledge-processes which are more ana- lytic than sjmthetic. Tliis conclusion goes to the very heart of the elementalistic position, and, as stated in the discussion on internal secre- tions, is really as much an epistemological as a biological problem. Reverting again to Loeb's writings, the conclusion to Implications of ihc Theories of Ner-r Action 207 which WL' are forced joins issue witli the very oiK'ninf sen- •.I ^^ tence of tlie Phi/sioloyi/ of the Brain, as we have ahM-ady in- dicated. "The understandinfr of c()ni|)licated i>hen()niena," particularly as presented by orfranisms, can not \ye accom- plished tlirou"h "an analysis by which they are resolved into their simple elementary components." Unquestionably an- alysis is essential to, but it is not adequate for, full under- standing of the phenomena. The very nature of organic synthesis and of hnojcledi/e- getting precludes the possibility of attaining the hind and degree of understanding of organisms xchicJi eU'mentalist biology claims to have attained and promises to attain. "A com])lete explanation of life in terms of physics and chemistry" is impossible for the sufficient reason that physics and chemistry ^.9 such do not contain any of the really dis- tinctive terms of life. Those terms can only be broufirht into physics and chemistry after and not before the phe- nomena of life have been searchingly scrutinized ; that is, an- alyzed and found to involve physics and chemistry. The terms of life are in the original data on the phenomena of life, and no sort of analysis can possibly make this other- wise. Our position, it should be noticed, touches the hackneyed controversy over vitalism and materialism only in so far as the course of reasoning we have pursued involves the recog- nition that each organism (the dog, for instance) is a natural object possessed of certain causal ])owers, by ex- actly the same logical and epistemological criteria that any simple chemical element or chenucal compound is a natural object. Stated in a brief and common-sense way, our contention is that the attributes which make a dog a living body an- no less natural than are the attributes which make carbon a chemical body. The tiresome and meager-frnit*(l contro- versy between Materialists and N'italists may l)e ch/iracter- 208 The Unity of the Organism ized as due to the fact that neither party has taken the trouble to estabhsh clearly, even in their own minds, the meaning of the word natural. As a consequence of this slipshodness the two groups agree tacitly, in treating the inorganic and the organic worlds as though natural does not mean the same thing in the two realms. The implica- tion is that if the inorganic world, for instance, be held to be natural by both parties, for the Vitalists the living realm is largely ^z^per-natural, while for the jNlaterialists the same realm is largely iw/ra-natural. Theories of Animal Behavior in Relation to the Science of Zoology This somewhat protracted though wofully insufficient treatment of neural integration may close with a brief section on some of the still larger biological and methodo- logical implications of the conclusions reached. Special at- tention is called to the fact that the culminating part of our argument has involved data and fconceptions which are as unequivocally zoological, morphological, and physiologi- cal, as any of the data and conceptions are unequivocally physical and chemical. Physical chemistry, or any other aspect of inorganic chemistry, is utterly powerless, so far as we can see, to discover such facts, as for example, that oxygen, carbon, nitrogen, etc., possess latent "doscarecious" powers. This final section is in the direction, consequently, of establishing the parity, to claim the least, of zoology, botany, morphology, and general physiology, with chemistry and physics, in the great complex group of biological science. We may first allude to a favorite mode of expression of materialistic elementalists. Whenever fuller analysis has proved some group of animal phenomena not hitherto con- nected directly with jihysico-chemical substances and forces. Implications of the 'lliconcs of Nerve Action ^Oi) to be in reality dependent on such a^eneies, this sclior)! !«, wont to remark in substance that investifration lias finallv "transferred" the phenonuiia t'loiii tlic provinces of /ooln^v, in()r})hol()^y, general ])hvsioloi»v and the othci* sciences of animal life, to ])hy'Sics and chemistry. Our ar- stance, that the factor in mental life which Wundt's school defines as 'Apperception' . . . may well be treated, from the purely psychological point of view, as the conscious aspect or accompaniment of a collection of tendencies of the type which Loeb has called 'tropisms.' " ^ Then we have: "Wundt has insisted tliat his 'Appercep- tion' is no disembodied spiritual entity. I conceive that Loeb has indicated to us, in the conce])t of the 'tropisni,' how a power more or less directive of the course of our asso- ciations, and more general than is any of the tendencies that are due, in us, to liabit, or to specific experience, can find its embodiment in the most elemental activities of our organism." ^ What, now, is the bearing of this idea of Royce's on the main theme of this chapter, the organism's unity as mani- fested in and influenced by its psychic life? As an initial step toward answering this question, tlie rcuhr Is asked to 222 The Unity of the Orgamism recur to the chapter on tropistic activities and their an- atomical groundwork, recalHng that it was the special aim of our discussion to show the inevitable organismal trend of the whole doctrine of tropisms. It should be remembered also that trojjisms are, all of them, probably, beyond ques- tion adaptive in fundamental nature; i.e., they work in the interest of either the individual as a whole or of the species to which the individual belongs. The circumstance that under occasional more or less artificial conditions the ac- tivities of an animal may result in injury to it or even in its death, is not proof that on the whole those activities are not advantageous. A horse or man may make himself sick now and then by taking the wrong kind of food or too much food, but this does not prove eating to be useless on the whole, or non-adaptive. Another important thing to bear in mind about tropisms is their automaticity, or preferably their intrinsicality. They are rooted in and partake of the very essence of the or- ganism — so much so that they manifest themselves inevitably when the right external and internal conditions are present, whether the general ends which they normally serve are at- tained in the particular instance or not. The flight of the moth toward the flame, even at the sacrifice of its life some- times, is a manifestation of a tendency that works, on the whole, for the good of the animal. That the moth follows the impulse even to death merely shows how tremendously deep-seated this type of reaction is. That the activity may result in injury or death in a special case is just because the case is special, i.e., it is a departure from the regular con- ditions under which the reaction-type became incorporated in the organization of the creature. Being always poised for a particular kind of action, and having a supply of en- ergy to execute the action, are unquestionably among the most distinctive attributes of animal organisms. Such or- ganisms are distinguished from plant organisms not only Psychic Integration 223 bj the present fact of inlKrunt activity of tlie animal, hut by their inherent preparedness for acting to meet new and more or less unusual situations. This action and action- readiness are the real meaning of the neuro-muscular syst( ni. All biotic organization is anticipatory in various ways, hut ainmals are almost exclusively anticipatory in action. It IS just these attributes that lloyce recognizes as com- mon ground between certain of the highest psychic activi- ties of man and tropistic activities. With this over})lus, and in some cases useless or even injurious activitv (in- stanced by the flight of the moth toward and around the fiame), let us now pass to the uj)])er end of the gamut of animal activity for illustrations. A very few must suffice. The first chosen is one of exalted creativeness in art. From the vast domain of art a more instructive illustra- tion of over-wealth of self-activity can hardly be found than is afforded by William Shakespeare. A recent investigation of his works undertaken with a view to finding what they tell about the "native endowments of the author" and prose- cuted with that love for accurate, exhaustive knowledge which is the very soul of modern science, leads to the result that of these endowments "the most outstanding perha])s is his exuberant vitality." This characteristic of the man i."> exhibited in the "reckless volubility of almost every cliar- acter, the piling up of fancy upon fancy, of jest upon jest, the long embellishment of humor and foolery and h()rse])lay for no other reason than the delight thev afford." ' And incidentally, the strict individualism of this sort of thing is exemplified by one of these same Shakes])earian characters: "Come, come," says Mercutio to l^cinolio, "thou art as hot a Jack in thv mood as anv in Italv. . . . Nav, an thrre were two such, we should have none shortly, for one would kill the other." "What has Queen Mah to do with tiu- ac- tion of the play of Rojnro and Juliet? Nothing; l)ut Mcr- cutio mentions her, and before any one can stop lu'ni he has 22-i TJie Unity of the Organism poured forth fifty lines of purest fantasy. . . . Whole scenes," this student declares, "exist for no other reason than that the author's brain is teeming with situations and humor and infinite jest." ^ Now I hear in imagination expressions of astonishment, rising to protest, even to ridicule, on the part of some biol- ogists, and to horror on the part of some literateurs, at the idea of suggesting that there is anything really in common between the two groups of phenomena here placed side by side — the activities of a moth and of Shakespeare ! For the moment I do no more in reply than ask the reader to take cognizance of the fact that the whole training and occupa- tion of the naturalist consist largely in comparing all sorts of things, inorganic as well as organic, which to cursory observation seem unlike, for the purpose of finding whether closer and broader examination can not discover resem- blances and affinities which may throw light on the ever- insistent problem of origin and causal relationship. From that procedure, and that alone, initially, came the theory of organic evolution. It is the quintessence of the organic method. To him who is so instructed and disciplined that the recognition of likeness and kinship between, for example, the prothallus of the fern and the flowering plant, or between a horse's fore-foot and a man's hand, will receive no shock from the comparison. The intrinsic justification of the comparison will be deferred until we have a few other illus- trations before us. Another illustration will be taken from an author, J. J. Rousseau, whose activities stand about mid- way between art proper and science proper. "I felt," Rousseau says in his Confessions, "that writing for bread would soon have exhausted my genius, etc.," Again : "Nothing vigorous or great can come from a pen totally venal." And finally: "In a severe winter, in the month of February, and in the situation I have described, I went every day, morning, and evening, to pass a couple of Psychic J ntcy ration 225 hours in an open alcove wliich was at the bottom of the garden. ... It was in this pLace, then, exposed to freezing cold that without being sheltered from the wind, I composed, in the space of three weeks, my letter to D'AK-iulxrt on theatres." If this sort of thing, one may note in passing, is a case of "struggle for existence," the existence struggled for is on the highest plane of j)sychic life and not on the j)lane of mere brute continuance. The only other example will be one of activity in science proper, i.e., "pure intellect" as far as there is such a thing. The case of some man devoting the best of his life to the working out of a great germal idea — an Aristotle, a Coper- nicus, a Galileo, a Kant, a Darwin will serve our purpose best. Of these we choose the case of Danvin. Consider first the youth and the young man keenly alive to the flood of sense impressions pouring in upon him from external nature, and mentally — "internally" — "restless," as Royce would say, from an undefined though strong dissatisfaction with the stereotyped school and university curricula and modes of dealing with subjects. Later comes the set of environ- mental influences (chiefly through the naturalist Henley), quite incidental to his regular, prescrilx'd environment, to which he responds with eagerness and effectiveness — an al- most automatic choosing of fields of intellectual activity. Out of all these fragmentary and by-thc-way experiences — "contents of consciousness" — there is organized a body of natural knowledge, and such definiteness and j)n)mise of ten- dency as to justify an appointment to a post of consider- able responsibility and unique opportunity, that of natural- ist to H. H. Exploring Ship Beagle. During the voyage and from the new and strange con- tacts with nature afforded by it, there arises another state of "restlessness," this time concerning the origin of organic species, the "mystery of mysteries," as Darwin himsrlf put 226 The Unity of the Organism it. A matter deserving special notice is that the truly for- ward, the creative step came after, and was conditioned upon, a period of dissatisfaction with the prevalent teaching on the subject. Then the considerable time of semi-con- structive observation and thinking and feeling under guid- ance of the general surmise that species arise naturally and not supernaturally, as all his earlier experiences — "contents of consciousness" — had taken for granted. And at last the final, for him, great conception, the hypothesis of the "strug- gle for existence" and "survival of the fittest" as a cause of the transformation of species. The suddenness and spon- taneousness with which this idea emerged into consciousness should be specially noticed. Once the merest suggestion of it hove in sight, the whole hypothesis formed itself, organ- ized itself, rapidly and completely. The sense in which the process may justly be called spon- taneous is important. Although we well know that the famous hypothesis was suggested by the reading of Malthus' work on population, we know equally well that the most es- sential features of the hypothesis were not contained in the teachings of Malthus. There was something genuinely new in the hypothesis. Out of the former total of experiences came that which did not actually exist in those experiences. Although the hypothesis was clearly a product of something which went before, it was a synthetic product in the strictest sense, in essentially the sense that a chemical compound is a synthetic product of its interacting elements, the sense that the most distinctive attributes of the compound can not be found in the elements taken separately, but only after the interaction has actually occurred. We must not fail to consider the long period of Darwin's strict "self-activity" in collecting evidence, pro and con, bearing on his hypothesis ; and the activity designed, notice, to ascertain whether or not there is a process going on in the outer world of plants and animals corresponding to the Ps/jcJi'ic I nf (•(/}•(! f}(ni 227 l)roccss he had conceived, i.e., Iiad pictured in his "inner world" of consciousness. 'V\\v ncnnineness of \\\r individual, the personal, the unicjue eharaetei- of mental hfc and nuiital creation can hardl^^ be more strikingly illustrated than by such cases as this of Darwin's when the conce|)tion, the \\\- pothesis, is kept to one's self so h)ni;- in oi'dci- "to prove'' whether it is "true" or not. Now I want to call particular attention to the indul)itable fact that these illustrations are oidv extreme manifesta- tions of attributes which are universal in the human animal at least. There is no normal human known to antliropolo^y which has not some measure, no matter how small, ot" creative impulse in art and in science. As a conclusion to this presentation of instances I nuist again insist upon one of my cardinal points: that the in- clh'idually active and creative power of the human oi'^anism on its psychical side is not a whit less real, less objective, less a natural phenomenon to the natural historian than is the hidhiduaUij creative power of physical growth and variation, and reflex and tropistic action. Indeed, the thorough-going, consistent zoological naturalist, the substance of whose science is largely animal behavior in all its aspects, can not possibly approve the effort to separate com]iletely the two sorts of creation. First Move Toward Shouing the Orgamsmal Character of the Higher Pay chic Life Now for the further scrutiny of such i)sychical facts as those typified by the exam})les i)reseided, for the j)ur ])ose of seeing what has been done and may yt t l)« done to- ward brino-ino- them into accord with the organismal con- ception, the pole star of all our |)nvious discussions. 'I'his examination will begin, as others have begun, by shownig how elementalistic attemi)ts to interpret organic j)henom- 228 The Unity of the Organism ena soon reveal their inadequacy and finally break down as the efforts come to face the increasing complexity which progress of objective research always finds in such phenom- ena. Associationist Psychology a Special Case of Element alist Biology In the particular psychical realm we are now to examine, elementalist theory has appeared most prominently as what is called Associationism. This flourished first in England as the school of English Associationists, David Hartley, near the middle of the eighteenth century, being usually consid- ered its founder. Psychologists of this group hold that ideas, which for them appear to be identical with sensations, are the "ultimate elements" of psychic phenomena. "Ac- cording to this theory, rigidly carried out, all genesis of new products is due to the combination of pre-existing ele- ments." ^ Even the passions, according to Hartley "must be aggregates of the ideas, or traces of the sensible pleas- ures and pains ; which ideas make up, by their number and mutual influence upon one another, for the faintness and transitory nature of each singly taken." ^ The "piling up of fancy upon fancy, of jest upon jest, the long embel- lishment of humor and foolery and horseplay" which Pro- fessor Manly shows characterize many of the Shakespearian plays, would be explained, according to this kind of psy- chology, not really by the author Shakespeare but by the "aggregation," in some way, within him of ideas. And, similarly, the works which in popular language are said to be by a Darwin, a Humboldt, a Copernicus, an Aris- totle, are in reality not by but merely in these men. The men were only the places of aggregation of the elements — the ultimates — by which the teaching on the origin of species, on the general character of the earth, on the solar system, Psjjchic Intrgrdfion 299 on the (iL'oj)t'r ineniiiiin- of cxtrinal natiirc, were produced. Again the old story witli which we have iK'conie faniihar: not the organism, but elements of, or perhajjs merelv In it, are the causal explanation of whatever occurrences are associ- ated with the organism. It is, I think, safe to assume that both the merits and the demerits of associationi^l psychol- ogy have been made })atent enough, at least to English- speaking students, by the writings of James and others. If only the doctrine of "association of ideas'' can be satis- fied to do what it is really able to do, and not insist upon trying to do what it can not do, its usefulness is great and its permanence in psychology assured. As indicated above, the "huge error," as James expresses it, by which the "whole historic doctrine of psychological association is tainted" ^^ is only another miscarriage of the elementalist mode of reasoning, and so is subject to the general type of criticism which the reader has met in every chapter in this book. In order to divest the criticism as much as possible of personal flavor I shall make large use of James' language. "All these writers," says James, referring to Ilohbes, Hume, Priestley, Hodgson and the later English associationists, "hold more or less explicitly to the notion of atomistic 'ideas' which occur. In Germany, the same mythological suppo- sition has been more radically grasped, and carried out to a still more logical, if more repulsive, extreme, by Ilerbart and his followers, who until recently may be said to have reigned supreme in their native country." Now the objection to the doctrine of "atomistic ideas" does not so much concern the conce])tion of ideas as atoms as the nature attributed to these atoms, namely in assum- ing them to be immutable, and sufiiciciit in their isolate capacities to account for the thought and other products arising from their "association." The following two (juota- tions illustrate the form this criticism, the essence of which 230 The Unity of the Organism is now very familiar to us as biologists, takes when it ap- pears in garments of a psychologist's making. The "huge error" of the association doctrine, mentioned above, James explains, is "that of the construction of our thoughts out of the compounding of themselves together of immutable and incessantly recurring 'simple ideas.' " ^"^ If there be any doubt as to the meaning of this surpris- ingly un-James-like wording, there certainly can not be as to the following: "For Herbart each idea is a permanently existing entity, the entrance whereof into consciousness is but an accidental determination of its being. So far as it succeeds in occupying the theatre of consciousness, it crowds out another idea previously there. . . . The ingenuity w^ith which most special cases of association are formulated in this mechanical language of struggle and inhibition, is great, and surpasses in analytic thoroughness anything that has been done by the British school. This, however, is a doubt- ful merit, in a case where the elements dealt with are arti- ficial ; and I must confess that to my mind there is something almost hideous in the glib Herbartian jargon about Vorstel- lungsmassen and their Hemmungen and Hemmungssummen, and sinken and erhehen and schwehen, and Verschmehungen and C omplexionen.^^ ^^ The long and short of the "huge error" of associationist psychology is that ideas are no such independent, immutable, simple entities as the doctrine supposes ; that in their origin and in all they are, and all they do, and all that comes forth from their association, they are in some sort and measure dependent upon — what? Something. Search after this something has been a large motive of more recent psycho- logical inquiry. One way of supplementing and rectifying associationist doctrines is to epitomize the shortcoming of these doctrines in the statement that they recognize only the objective side of the association process, whereas the subjective side is Pfsijcliic Intccjrafion 231 equally ini])ortant. 'Hius Pillsl)iiry : **U was a nv^Uci of the subjective conditions and the insistence upon the ohjec- tive side of the problem that lias led the Knheres, have a relation to each other too important for the earth sciences to ignore or even to })ut oft' as merely "paralKl.'" But when it comes to an entity like a live animal, the cpiin- tessence of which is organization, the (jucstion of how two of its "sides" so important as its objective and its subjec- 232 The Unity of the Organism tive are related, becomes most fundamental, especially when a subject like that of ps^^chical association is up for con- sideration. It is, then, fundamental to our enterprise to find out all we can about the connection between the objective and sub- jective aspects or sides of the organism. It would be folly to expect results of any value from an effort of this sort without having first given attention to the nature of each of the sides. Now the objective "side" comes to much the same thing as the physical or material organism as we are conceiving the "sides." But since this has been the sub- ject of our whole treatise up to the last two chapters, and even of the greater part of these, we are already possessed of enough understanding of this "side" for our present purpose. As to the subjective "side" the case is different. Into its nature, its makeup and activities, we have looked very little — only in a bird's-eye-view fashion thus far in the present chapter, and into its marginal or transitional zone in the preceding two chapters. We are, consequently, obliged to penetrate further into the subjective realm itself before the main problem, that of the relation between the sides, is attacked. The Essence of Wundtian Apperception This carries us back to tlie point at which we brought Royce's suggestion of a relation between Loeb's tropism theory and Wundt's apperception theory into the discus- sion, the return to this point being for the purpose of using Wundt's conception to induct us further into the nature of mental life. The importance of examining Wundt's con- ception is two-fold. In ihe first place, we want to know whether or not it is genuinely descriptive of man's highest psychical life. If it is, nothing can stand in the way of its Psychic Integration 233 acceptance, so far, by tlie anthropological zoolorrjst. But in the second place we must know wlu'tiicr or not it carries, as some critics believe it docs, transcendi-ntal or supernatural- istic implications. If this charge be true it is of course to this extent unsanctionablc from our standpoint. Wundt's most concise characterization of ajjperception which I have found is, "The process by which any content of consciousness is brought to clear comprehension we call apperception." ^^ A content of consciousness is any definable experience wt* may have. All consciousness whatever is consciousness of something or other. This "something or other," no matter what, nor whether regarded as a whole or in part, is a con- tent of consciousness, according to my understanding. What is most distinctive about Wundt's characterization may be regarded as centering around the word clear. When a particular content gets itself into the lime-light of con- sciousness — when it becomes the center of attention — the process by which it does so is apperception. On the other hand, the process by which contents, though brought into consciousness, come only into its outer zones or edges, and do not monopolize attention, is perception. Though tiiis getting of a content into clearness in consciousness, this monopolizing of attention, may take place passively or actively so far as the mind as a whole is concerned, the ac- tive way seems to be the more distinctive and important, at least for mental life as a whole. It is apparently this positive activity of appcrce])tion, directed toward making ])articular contents of conscious- ness clear, which has brought criticism upon Wundt's con- ception. "Wundt talks," says Pillsbury, ''almost as if there were a faculty or force of apperception, something behind and superior to consciousness, which brings about the change in clearness of the impressions. There is in the brain a definite centre of ap])erception, and in conscious- 234 The Unity of the Organism ness a force very closely related to will, that in and of itself chooses certain ideas for elevation to the high places of consciousness, and equally arbitrarily rejects others." And then follows this in Pill8bur3^'s criticism, which brings out unmistakably its real purport : "It is very much like the self-conscious unity of apperception of Kant, which gives the final form and order to the various disconnected elements of the mind, and is in so far something inexplicable, a factor in experience that must be assumed without any further discussion of its nature, origin, or laws of action." ^^ A suspicion, obviously, that the transcendentalism of Kant broods over Wundt's theor}'. As to tlie justification of this suspicion we need not be concerned here. Enough for us at this point to recognize that from the standpoint of description as natural history practices the art, or aims to practice it, Wundt's account of the way the mind works in a vast range of its activities seems true, and as far as it goes is satisfactory. Not only the matter of clearness of the contents of con- sciousness, but their makeup as well is important. Al- though "psychical elements" figure largely in Wundt's sys- tem, one finds no intimation that the whole mind and its contents can be "explained" by reducing them to "ultimate elements" after the familiar manner of elementalist explana- tion. "All the contents of psychical experience," Wundt says, "are of a composite character." And it follows from this that ''psychical elements, or the absolutely simple and irreducible components of psychical phenomena, are the products of analysis and abstraction." ^^ The two words, "analysis" and "abstraction," need par- ticular consideration. The psychical elements found by analysis do not exist, as such, in nature. Analysis, in this case, is logical or thought-analysis, and not objective analy- sis. We should do well to recall what was said in the dis- cussion of reflexes, namely that the "simple reflex," though Psijchic I ntcy ration }i.'J5 legitimate and useful as an aid to i.derprcting the plunnm- ena of reflex nerve action, lias no actual cxistcncr in nature. It, like the "psychical element,^' i> .ui abstraction. This is only another way of saying that psychical d.ni.nt^ are what they are because they are parts of the mind as a whole, just as we have seen over and over again physical elements of the body are what they are because they are i)arts of the body. "The specific character of a given psychical process dejjends for the most part not on the nature of its elements so much as on cheir union into a composite ])sychical com- pound. Thus, the idea of an extended body or a rhvthm, are all specific forms of psychical experience. But their charac- ter as such is as little determined by their sensational and af- fective elements as are the chemical properties of a comjjound body by the properties of its chemical elements. Specific char- acter and elementary nature of psychical processes are, ac- cordingly, two entirely different concepts." ^'^ We must not miss an essential point in this, that since with psychical elements just as with chemical elements we never know exactly what or how nuich each ])articular ele- ment contributes to the compound, we are obliged to con- ceive the attributes of the compounds as pertaining to the elements collectively even before the compounding lias K-en done. So it comes about that because all contents of conscious- ness are fundamentally com})osite, but are also resolvable into components of various grades of complexity, synthesis and analysis have a prominent place in tlu' \\'un(ltian system. Of these, synthesis is the more definitive and fundamental, since it enters into the verv nature of c()ii>(inii>ness itself. Consciousness is, according to \\'undt, the ''inter-connec- tion of psychical compouncis."" "It is the name for the gen- eral synthesis of ])sychical processes, in which synthesis the single com})ounds are markid off as more intimate combina- tions." ^^ The meanino- of this is made clearer bv the state- 236 The Unity of the Organism ment that unconscious states like deep sleep, faint, and so on, are the interruption of these interconnections. Remarks On Analysis and Synthesis This brings us to where we can see the important distinc- tion between an aggregation and a synthesis — in a psychical sense particularly — and hkewise between a fragmentation and an analysis. No mere aggregation,* as of ideas or emo- tions, would make consciousness. Only a synthesis of con- stituents can do that. And, contrariwise, while the mere severance of the synthesized components produces uncon- sciousness, an analysis of them results, not in unconscious- ness, but in a consciousness of the constituent parts of the contents of consciousness. The essence of consciousness is unitariness — integratcdness, in our general terminology — as regards the contents of an individual organism's psychical nature, so that whatever analytical processes the mind per- forms must move within the bounds of its own unitariness or integratcdness. Were we to conceive the analytic opera- tions of the mind to exceed or even quite to equal its synthetic operations, we should have to conceive it as utterly negating consciousness, i.e., as destroying itself. A man could ana- lyze his own mind in an elementalist sense only by suiciding. In other words, he could never do it, simply because he would have killed himself by the very process of analyzing before he had completed his job. These remarks on the distinction between synthesis and aggregation, and between analysis and fragmentation, are not quite what Wundt sa^^s. They go somewhat beyond his actual expression, but are legitimate inferences, I am quite sure, from his discussion as a whole. And they help us toward what we want to accomplish, namely to discover still more * Recall our previous remarks on this subject, e.g., pp. 183 and 268, and also the quotation from Hartley, p. 228. Psijchic Integration 237 than Rojcc discovered about the relation between ai)percep- tive processes, as Wundt conceives them, and the processes known as tropisnis. Anticipating our results, and stating them in the most general terms possible, we may say that the "apperceptive synthesis" of Wundt, and what may be called troj)istic syn- thesis, have a common ground in the kind of synthesis which is the very essence of that kind of organization to which the term life is ap})lied. To be alive is to be an organic in- dividual; to be an organic individual is to be an indi- vidual that perpetually synthesizes itself from substances extraneous to itself (food, in the narrower sense, and oxygen) ; and to be a psychically endowed individual is to be an individual which in addition to synthesizing a physical nature from the substances mentioned, synthesizes a psychical nature from physical and chemical contacts and interactions between the individual and the external world, the physical contacts being called stimuli. ^'iewing the matter thus, it is seen to be highly probable that in its ulti- mate essences the dependence of the psychical nature of the organism on stimuli is connected, directly and inseparably, wdth the dependence of its material nature on material nu- triment. We should, I think, be surprised were a demonstration to be produced that psychic life has as little connection with metabolic processes as the text-books of psychology would lead one to suppose. Every modern psychologist, like every modern biologist, accepts, unquestioningly I presume, the conception that in some icay the psychic life is no less de- pendent on the nutritive substances and processes than is the physical life. Yet that "some way" ai)pears to Ik^ gen- erally regarded as so remote and obscure as to be U^vond the reach of profitable treatment by psychological science, judg- ing from the considerable number of standard text-lM)oks which I have consulted on the point. In only one of these 238 The Unity of the Organism {Elements of Physiological Psychology, by Ladd and Wood- ward) do I find the word "metabolism" in the index. Our task may then be restated as that of making out more fully and clearly than Royce did the connection be- tween apperception and tropisms, which is involved presum- ably in the whole problem of organic synthesis from its highest manifestations in psychic synthesis to its lowest manifestation as metabolic synthesis ; of bringing to more specificity the general statement made above. But such statements are altogether too sweeping and abstract to satis- fy scientific description and explanation in our day. A chapter must now consequently be devoted to making them more definite. REFERENCE INDEX 1. Hobbes 2. Hobbes 3. Hobbes 4. Royce 5. Royce 6. Royce 7. Manly 8. Manly 15 21 25 ix X xi 3 4 9. Baldwin I, 80 10. James ('90) 1,553 11. James ('90) I, 603 12. Pillsbury 106 13. Pillsbury 112 14. Wundt 229 15. Pillsbury 270 16. Wundt *. 32 17. Wundt 33 18. W^undt 223 Chapter XXIII ORGANIC CONNECTION HirrWKEN PIIVSK AL AND PSYCHICAL A Still Closer Look at the Organistnal Nature of Tropisms TTAVING selected tropisms as a strategic point in our A A |)rogram of search for tlie vital connection, if siidi exists, between the physical and tlie psychical, we must turn again to this subject. Our previous treatment of tlie tro- pism theory brought out the essential organismal character of the type of activity to which the term tropism has been applied. Tlie result of that treatment might Ix? epitomized by saying that in so far as the theory rests 'on accurate and adequate description, it is genuinely organismal and genuinely sound, but in so far as it rests on causal ex- planation that is elementalistic in spirit and expression it is genuinely unsound. Our present aim will be furthered by illustrating this epitomized stricture on the theory in a little different way from which we objectified our criticism in the earlier treatment. Every one familiar witli cunrrit explanatory disc'ussion of tropisms must have noticed the large and free manner in which the word substances is made use of In the explanations. Thus, to illustrate: The larva^ of certain butterflies tnu'rge from their winter nests under the Influence of the warm spring sunshine, crawl to the tij)s of the branches of some shrub or tree, eat the buds and tender leaves there; then, after feeding to satiety "turn tail" and crawl down the 239 240 The Unity of the Organism branches. This rather complex and, to the insects, highly useful performance Loeb and others have proved to consist of a series of reflexes so interconnected as to come under the tropistic type of activity. And Loeb, e.g., in the chap- ter, On the Theory of Animal Instincts (Physiology of the Brain) uses the case to good effect in support of his contention that the traditional instinct-and-nerve-center ex- planation of such phenomena is utterly inadequate. So far, good. As to the straightforward presentation of facts, Loeb's position seems unassailable. But what about the causal explanation of the facts.'^ What, exactly, is it that sends the larvae up the branches.'^ What causes the eating activities.^ What makes the creatures then turn about and finally sends them down the branches.^ That several environmental factors, the warm weather, the sunlight, the character of the plant buds and leaves, and so on, are involved is brought out clearly enough. But what about the factors pertaining to tlie larvae themselves.'^ The body-shape, the skin, the sense organs, the muscles are, as was emphasii^ed in the previous discussion of tropisms, freely recognized after a fashion by the tropism theory. But deeper still than these — what.^^ Chemical substances "ac- cording to requirement," in the language of the cook books. Until the caterpillars have taken food they are positively "heliotropic," that is, literally, are induced by sunlight to move toward the sun, after the higher spring temperature has caused chemical changes in their bodies essential to such movement. But by eating to satiety the chemical changes essential to the positive heliotropism are inhibited and a negatively heliotropic state comes on. "We can im- agine," writes Loeb, "that the taking up of food leads to the destruction of the substances in the skin of the animal which are sensitive to light, upon which substances the helio- tropism depends, or that through the consumption of food the action of these substances is indirectly prevented." ^ In Organic Connection Between Physical and Psychical 241 the total scheme, then, actual and iniacrincd, various "sub- stances" are indispensable. That the imaginary constituents constitute a very im- portant part of the exphmation is obvious. This fact is, however, not specially objectionable. It is not if its tiiu' character is never forfrotten. But here comes the point 1 wish to make focal just now. If imagination is to be given a place at all in the argument it must have a larger place than Loeb has accorded it. Othei-wise the teachings of evolution, i.e., the genetic continuity in biology, are tacitlv repudiated. Attention has previously been called, especiallv in the chapter on the organism and its chemistry, to the deep current of virtual anti-geneticism which runs through physi- ology generally, and particularly through bio-chemistrv. Undoubtedly we can imagine "substances" produced and de- stroyed in such a complex of activities as that described, to meet exactly the needs of the larva ; but can we legitimately imagine them to be so produced and so destroyed by any other means than just by the particular animals in question, that is, by the organisms? Various of our discussions, but particularly those in which the specificity of protoplasm have been dwelt upon, constitute a decisive negative answer to this question. Xo causal ex])lanation of the requisite "substances" imagined can stop short of the organism^ alive and normal, as an essential and "causal factor" in the phe- nomena presented. Causal explanation of tropisms which aims to reach a physico-chemical basis is really organismal as well as are tropisms seen through the medium of ]Mire description. The Automatic and Anticipatory Character of TrojJisni.s una Other Reflexes Nor should the reader fail to note the intrinsicality, the adaptiveness, and the anticipatoriness, of tropisms as illus- 242 TJie UniUj of the Organism trated in this example. Conscious will and choice seemingly do not come into the operation at all. Given the right con- ditions, internal and external, the caterpillar goes through the concatenation of operations necessary for its existence, willy-nilly. Moreover, the actions initiated by the warm weather, the larvae being yet down at the base of the shrubs or branches, have in organic prospect, as one might say, a supply of food peculiar to the species. And this supply, be it remarked, is several inches at least, and several min- utes at least, away from the larva at the beginning of its round of activities. Its future, even more obviously than its present, existence is involved in the acts. Anticipatori- ness is perhaps the most conspicuous attribute of the adap- tiveness of such activities. C. Lloyd Morgan has well ex- pressed the truth that one of the most important lessons to be learned from the study of animal behavior "in its or- ganic aspect" is the fact that "living cells may react to stimuli in a manner which we perceive to be subservient to a biological end, and yet react without conscious purpose — that is, automatically." ^ But from our examination of the cell-theory we conclude that "living cells" in this statement ought to read "living organisms." So much by way of further preparation, in the reflex and tropistic phases of animal life, for our search after a vital connection between the physical and the psychical. It will now be advantageous to return to that supremely important aspect of human psychic life already examined somewhat, namely that of Wundtian apperception. A Still Closer Look at the Likeness Between Higher Ra- tional Life and Tropisms As Royce's statement of the objections to the concep- tion of Wundt contains several points that will be useful to Organic Cormection Betzveen Physical and Psychical 243 us, we reproduce more of his sentences. ''It has been ob- jected to the partisans of Wundt that the tcriii 'appercep- tion,' as thus used, seems to signify a factor in mental life which can be explained neither in terms of what we have called sensitiveness, nor in terms of the law of habit. It has also been objected that the conception of a conscious process, engaged in influencing its own states, is a concep- tion which confuses together metaph3^sical and psycliolog- ical motives. The psychologist, engaged as he is, not in studying how Reason forms the world, but in observing and reducing to rule the mere phenomena of human mental life as they occur, is not interested, it has been asserted, in a power whose influence upon mental phenomena seems to be of so ambiguous a character as is that which the Wundtian 'ap- perception' possesses." ^ Again : "This is the place," Royce writes, "neither to expound nor estimate Wundt's theory. But it does here concern us to point out that what occurs in mind whenever we are actively attentive is attended with a feeling of rest- lessness, which makes its dissatisfied mth all those associa- tive processes that do not tend to further our current in- tellectual interests. On the other hand, the cerebral proc- esses that accompany active attention are certainly such as tend to inhibit many associative processes thut would, if free, hinder our current intellectual interests .'* Mean- while, "owr active attention itself is always the expression of interests which possess the sam-e elemental character that we have all along been illustrating in the foregoing para- graphs. The attentive inventor is eager about the beau- tiful things that he thinks of while he is trying to invent. The attentive hostess is eager about social success. Thr attentive caged animal is eager about whatevi*r suggest^ a way of escape." ^ The discussion from which these sentences are taken is contained in a chapter near the end of the book, entitled 244 The Unity of the Organism The Conditions of Mental Initiative^ and in order that the reader may get the full force of what Rojce is talking about, he is earnestly recommended to read the entire chap- ter. Only thus can the "foregoing paragraphs" mentioned be adequately appraised. But we must try, in our own way, to get the essence of the matter. Royce's presenta- tion is his way of insisting upon the facts of psychical life and activity, high and low, which have given rise to the Wundtian conception of apperception, these facts being the indubitably initiatory, directive and selective qualities of mind in all its grades. Furthermore, Royce dwells on the homogeneity, as one may express it, of this intrinsicality of mental life — its initiative, its persistence, and its selectiv- ity — with the individual or fluctuating variations which have played so large a part in theorizing about organic evolution and heredity during the Darwinian era of biology. And he goes back still further in good modern biological fashion, and connects these variations with organic growth itself, thus calling attention to the fact that variations of this particular sort can not be referred to environmental influence. At this point we may stop, as biologists, to supplement Royce's argument by pointing out that variations of the sort indicated, are referable to environmental influence only in the sense that growth is so referable. An organism's securing and taking in of its nutritive substances are un- doubtedly a kind of response to contact with its environ- ment, and in that broad sense growth may be said to be due to environmental influence. If the organism had no nourishment, if it received no environmental influence of this kind, it certainly would not grow. At the same time, since the organism manages somehow to build a great variety of tissues and organs out of one and the same supply of nour- ishment; that is in response to one and the same "environ- mental influence" (as we are agreeing to use the phrase Organic Connection Between Physical and Psychical 245 here) there is no course open but to recognize that the or- ganism is a very important, because indis})ensable, factor in its own growth and differentiation. "Self differentiation," so far as the whole organism is concerned, is a fact than which no other in the whole domain of biology is better es- tablished. Indeed, self differentiation is really a special form of self growth and surely no one would contend that environmental influence is more than an essential factor in the growth of an organism. To hold it to be a complete explanation of the phenomenon would be too manifestly ab- surd to receive serious consideration. It would be to con- tend, in effect, that one of the processes of the organism (its growth) is more than all the processes of the whole or- ganism. But since most if not all variation depends, either directly or indirectly, upon growth, what is more natural than that the living, growing organism should display much self variation.^ That such variations are among the most common phe- nomena presented by organic beings, there is no shadow of doubt to any one who views the problem broadly and crit- ically, and with no domineering preconceptions as to what ought to be and ought not to be ; who, in other words, views the organic world as a natural historian, guided by the mandate "neglect nothing," instead of as a physicist in the mathematico-laboratory sense, guided by the mandate "neg- lect everything which can not be made to conform to gen- eral mathematically statable law." These remarks about the relation of mental activity to growth, differentiation and variation of the organism, and to environmental Influence would apply throughout, muta- tis mutandis, to troplstic activity. 246 The Unity of the Organism A Still Closer Description of the Suhrational Moiety of Psychic Life And this brings us to where our final return may be made for purely descriptive and comparative purposes, to the subrational moiety of psychic life, the purpose of the re- turn tliis time being to characterize this moiety as faith- fully but as briefly as possible on the basis of the total re- sults of researches in the field up to the present time. So bulky and varied are these results that to examine them exhaustively is hardly possible for any one person even though he be a specialist in the field. Much less possible is it, then, for a general zoologist to make such an examina- tion. Nevertheless it is, I believe, possible to give an epitome of the present state of knowledge that shall be true in all fundamental respects and liighly significant for our enterprise. Remarks on the Classes of Suhrational Life In giving this epitome we shall not try to maintain a sharp distinction between reflexes, whether of the tropistic or any other type, and instincts. To begin with, as always, when a large and intensively cultivated domain of science is en- tered for the purpose of extracting from it its most certain major results, we may take it for granted that the ex- tremists touching any portion of the field over which di- vergence is wide and warm, are unsafe guides for the gen- eral student. Thus, the student who enters the realm of animal behavior for such a purpose as that for which we are now entering it soon sees that those specialists who find nothing but tropisms, and these of the most uncompro- mising sort, in the activities of much of the animal king- dom, are not the ones to whose guidance he can entrust Organic Connection Between PJif/sical and Psychical 247 Iiiniself, no matter liow voluminous, and perhaps excellent in quality, their experimental researches may be. For instance, such a view as that of Bohn's, according to which the word instinct ought to be eliminated from the terminology of science ''as a legacy of the past, the middle ages, the theologians and the metaphysicians," ^ is so obvi- ously unjustifiable to any well-informed zoologist as to make him suspicious of such a writer all along the line, especially wherever his judgment and scientific poise are im- plicated. This question of the reality of instincts I use to Illus- trate the peril to the general student of the unpoised spe- cialist, because it is germane to the present discussion. In general zoology the type of animal behavior to which the term instinctive is applied is not less conspicuous and real, to say the least, than is the type described as tropistic. For an experimentalist to come out of his laboratory and tell a broadly experienced entomologist or ornithologist, for example, that the familiar achievements of young insects of many species, and of numerous young birds should not be called instinctive because (as the experimenter asserts) they are reducible to the tropistic or ])erchance the simple reflex type of reaction, may justly be characterized as sci- entific impertinence. It is as though an cmbryologist, hav- ing discovered that a bird's wing is the genetic counterpart of a salamander's forelimb, should Instruct the ornitholo- gist that it is wrong for him to call the bird's wing a wing, because the member may be reduced to a lower type of limb. Unquestionably the experimental specialist often pro- duces results which necessitate changes in the general zo- ologist's conceptions and nomenclature. Jkit it is not his province to take into his own hands the re\ision of the fundamental terms of zoology. Any one moderately In- structed in the history of zoology knows that ''instinct'' is a hardly less well-grounded zoological term than "birth" or 248 The Unity of the Organism "intelligence," or many another indispensable term. Our inquiry is not as to whether there are such things as instincts, but how they operate and what they signify for the animals possessing them. Perhaps of highest interest to us is the fact that innumerable instincts, if indeed not all, are as indubitably hereditary as are any animal endowments whatever. This comes out especially convincingly in those numberless cases where the instinctive operations develop strictly pari passu with the anatomical development of the young, there being absolutely no opportunity for them to learn, even subconsciously. Take as an example the crustacean Amphithoe longimana, in which Holmes compared in detail the activities of the newly hatched young with those of the adult. "Amphithoe lives in tubular nests which are usually lodged among sea weed. The nests are somewhat longer than the animal, and are spun of a web-like material into which bits of sea weed are often incorporated which help to conceal the oc- cupant. In its nest Amphithoe lies in wait for prej, ready to dart out upon any small creature which touches the ends of its long antennae. "The activities of the adult Amphithoe, with the excep- tion of those concerned in reproduction, are almost ex- actly paralleled by those of the young. I have taken the eggs from the maternal brood pouch shortly before hatch- ing and kept them isolated in individual dishes. For some time after emerging from the egg the young were weak and had imperfect control of their movements, which were jerky and irregular. Soon the minute creatures would crawl and swim much like the adults, and the next day they began constructing nests which were the same shape as those formed by their parents." Then comes a part of the description to which the reader's special attention is called because it brings out, partly by implication, a richness of detail in be- havior which defies full expression, and which every care- Organic Connection Between Physical and Psychical 249 fully observing zoologist knows to be characteristic of the activities of nearly all animals. Especial attention is in- vited to this, because this elusive wealth of behavior is usually overlooked by the cursory observer on the one hand and by the experimentalist on the other. "The attitudes in the nest," Holmes writes, "the waving of the antenna?, the beating of the swimmerets, the restless movements of the legs and mouth-parts, springing after food, belligerency toward passers by, the little unobtrusive signs of timidity, the reversal of position in the nest on the approach of danger and the general behavior outside of the nest, were, on the next day after hatching, almost exactly the same as in older individuals. The only differences in behavior were due to the feebleness of the young and their imperfect con- trol of their movements." One never reads a description like this by a typical experimentalist, especially if he be a pure tropist, or by a meagerly trained zoologist ! Then the final statement : "The young are hatched with all the in- stincts necessary fully to equip them for the business of life. No experience is necessary to teach them what is advan- tageous for them to do." ^ The impossibility should be noticed of drawing a sharp line in this description between instinctive and purely reflex acts. "Reversal of position in the nest on approach of danger" is clearly instinctive. But "beating of swimmer- ets," and especially the "restless movements of the legs" — are these instinctive or wholly reflex? Probably they arc reflex, though the leg movements may well be partly in- stinctive. A whole volume of examples as unquestionable as this could be compiled, and all groups of animals from mammals down to worms at least would be represented. 250 The Unity of the Organism Four Certainties About the Adaptiveness of Subrational Psychic Activities Concerning the purposefulness or adaptiveness of activi- ties of this general type, I think four things may be re- garded as absohitely certain. Generally Us,eful to Individual and to Species First, a vast majority of them are recognizably contribu- tory to the perpetuity of both the individual in its normal life, and of the species. But for them neither individual nor species would continue to exist. This is so obvious that further remark upon it is unnecessary. Many Useful to Species Primarily Second, in a large number of instances particular acts by particular indi\4duals are in the interest of the species primarily and of the individuals only secondarily or not at all. This is shown most conclusively in cases like that of several species of salmon, where the individual normally goes through activities which secure the continuance of the spe- cies but which end in the death of the individual. A large and varied number of cases of this type occur, especially among insects. But the supremacy of species over individ- ual needs appears under various other forms. Thus almost certainly such tropistic activities as that of the moth going to its death or injury in the flame is of this sort. This case may be stated in general terms thus : Owing to lack of any ability on the part of an individual to modify its in- herited mode of action to meet a special situation, it acts in the old way even though the new situation, while in gen- eral like the old, yet differs from it enough to make it peril- ous to the individual if it acts unmodifiedly in the old racial Organic Connection Between Physical and Psychical ^51 way. The preeminently racial utility and hereditary char- acter of instincts is certainly one of the most interestinrr things about them for the present discussion. Variability of Suhralional Activities The third certainty about reflex and instinctive activities is that they are b}- no means so stereotyped and invariable as older cursory observation or as much theorizing, espe- cially about tropisms and instincts, has held them to be. Darwin, in the notable chapter on Instinct in The Origin of Species, was the first to attack seriously the notion of such invariability in dealing with instincts. He undertook to show that the instinctive type of activity is subject to vari- ation just as are all other aspects of animal life. A telling set of recent investigations under this head is by the Peckliaiiis. That on tlie solitary wasp, AnimopliiUi ui'nariay is particularly to the point because the earlier writers had used its habits of paralyzing caterpillars by stinging them and storing them up as food for its young to illustrate the undeviating and unerring character of in- stincts. But the extensive studies of these entomologists led them to write : "The one preeminent, unmistakable and ever-present fact is variability. Variability in every par- ticular — in shape of the nest and the manner of digging it, in the condition of the nest (whether closed or open) when left temporarily, in the method of stinging the prey, in the degree of malaxation, in the manner of carrying the victim, in the way of closing the nest, and last, and most ini- ])ortant of all, in the condition produced in tlie victims l)v stniguig. ' No present-day authority so far as I know contends that instincts operate in a hard-and-fast manner comparable to the workings of any man-made machine. They are now universally recognized to be subject to the same general 252 The Unity of the Organism principles of variation to which all organic phenomena are subject. Furthermore, under the searching investigation and criticism of numerous workers, notably H. S. Jennings and his followers, the tropism theory has been deprived, for most biologists, of its inorganically mechanistic character. The principles of "random movements," "avoiding reac- tions," "trial and error," and others, are thoroughly estab- lished and the recognition of them may be said to have so modified the doctrine of tropisms as to make it one of or- ganic mechanism rather than of inorganic mechanism — as it virtually would be according to the thoroughgoing elemen- talistic conception of it. The "mechanistic conception of life," one may remark, has very much to commend it if only the machines conceived are recognized to be alive. My re- marks under this head * may be consulted by the reader who wishes to follow this point. What is meant by random movements is made clear by the following: "In the earthworm and the larvae of blow- flies which are negatively phototactic it has been shown by the writer that movements which bring the animal toward the light are checked or reversed and only those which hap- pen to direct the animal away from the light are followed up. Whatever immediate orienting tendency the light may have in these cases is relatively unimportant as compared with the element of selection of favorable movements in di- recting the animal away from the light." * Here it will be noticed that the end, beneficial to the ani- mal, is reached through a combination of orienting reac- tions of the rigidly tropistic type, i.e., the type dependent on the movement of the animal directly toward or away from the source of light by the symmetrical plan of the body, and a sort of reaction in which the particular body- form and the direction of light rays are of only secondary * See "Machines, living," in the index of The Probable Infinity of Na- ture and Life. Organic Connection Between Physical and Psychical 253 significance. But tlii.s latter type of activity, wholly di- vorced from a direct-orienting reaction, and even from a bilateral body s^nnmetry, is of wide application among the lower animals. It was first brought clearly to the atten- tion of biologists by Jennings in his now well-known inves- tigations on Paramecium and other protozoans. These in- vestigations formed the bases of the "avoiding reaction" and the "trial and error" conceptions now generally recognized to be of much importance in the behavior of all animals, es- pecially of those in which a high measure of bodily activity occurs but in which there is little or no intelligence. Jen- nings' lucid account of* his results in the chapter Be- havior of the Infusoria; Paramecium (Behavior of Lower Organisms) is strongly commended to the reader. The following paragraph must suffice for our reference to this w^ork. After describing the behavior of Parame- cium, Jennings writes : "This method of behaving is per- haps as effective a plan for meeting all sorts of conditions as could be devised for so simple a creature. On getting into difficulties the animal retraces its course for a distance, then tries going ahead in various directions, till it finds one in which there is no further obstacle to its progress. In this direction it continues. Through systematically testing the surroundings, by swinging the anterior end in a circle, and through performing the entire reaction repeatedly, the in- fusorian is bound in time to find any existing egress from the difficulties, even though it be but a narrow and tortuous passageway." ® And this complex and highly useful be- havior is performed by an organism which, so far as the best anatomical researches have been able to determine, is entirely devoid of a nervous s^^stem, and consists of a single cell! But the "trial and error" scheme here exemplified is by no means confined to unicellular, non-nervous animals, nor to experimentally produced conditions. That it is opera- 254 The Unity of the Organism tive in nature, and among animals with rather highly de- veloped nervous systems I shall illustrate by describing briefly a performance witnessed by me some years ago. This was the capture and engulfment of food by a nemertean worm.* These marine worms are of considerable size, some reach- ing a length of many inches, even a few feet, and ranging in thickness from less than an eighth of an inch to nearly an inch. Externally they give the impression of being very lowly in organization, the body being devoid of limbs or other appendages, and without segmentation. However, when they are examined internally a surprisingly high grade of organization is found, the muscular, digestive, blood and nervous systems being on a par, probably, with those of any invertebrates below the crustaceans and insects. The nervous system, particularly the brain, is relatively large, though not differentiated into diverse ganglionic masses and connecting strands to the extent found in jointed worms. The creatures are poorly equipped with external sense or- gans, there being no tentacles nor any certain olfactory or auditory organs. And eyes, when present, are so minute and simple as to be without power of sight in the ordinary sense; almost certainly they are mere light-perceiving or- gans. The most distinctive anatomical feature of the nemerte- ans is a very long and thin though muscular and flexible hol- low tube situated at the anterior end of the animal, which is usually carried stowed away in a pouch within the body. While thus retracted the tube has some such relation to the rest of the animal that a glove-finger would have to the * Greatly to my regret I am unable to say what the species or even the genus was of either the nemertean or the annelid here referred to. The observation was made at the Shumagin Islands, Alaska, and under cir- cumstances that rendered it quite impossible to "look up" the species. And my knowledge of the taxonomy of these groups of worms is alto- gether too meager to enable me to identify genera even, offhand. Organic Connection Between Physical and Fsychical '■Zi>:j glove were it coni2)letely inverted into the hand of the glove. This tube is used in the capture of prey, tlie ani- mals being carnivorous and highly voracious. The mode of employing the apparatus consists essentially in thrusting the tube out with almost the speed of lightning, the object being to bring the organ into contact with the prey at many points. The lash is not used as a lasso for catching or as a spear for piercing the prey, but for paralyzing it, prol>- ably by a toxic secretion spread over the whole surface. The more effectually to accomplish this, the lash is shot out at a victim again and again. Now for the aspect of the whole operation of food-taking which specially concerns us. Being quite sightless and touchless in the usual sense, the lash must be used as an ex- ploring or finding as well as a paralyzing or killing organ ; and since its great length and limberness preclude it from being used as an ordinary tentacle is used, the finding op- eration is accomplished by repeated out-thrustings of the tube. In the instance witnessed the prey was an annelid worm, a creature well provided w^ith locomotor organs, and a crood crawler. On this account the victim-to-be was able, in the early stages of the onset, to move out of contact with the nemertean now and then. At such times the prey could be relocated only by darting out the lash at random, except as to general direction. So it resulted that many of the thrusts missed the mark; but they were instantly repeated with a little variation of direction, till the victim was lo- cated again. The whole performance reminded one of the game of blind-man's-buff, a game in which the seeker paws around in the general vicinity, as he believes, where the one sought was last touched. The effectiveness of the try, try again method was at- tested in this instance by the fact that the annelid was lilt and the paralyzing dose administered times enough to put the annelid into so helpless a state that the nemertean was ^56 The Unit!/ of the Organism finally able to get its mouth into contact with its prey. Then the victim, itself but little smaller than the nemertean, disappeared down the latter's "throat" with almost the rapidity with which the lash was retracted into and thrust out of its pouch. How much of this highly complex per- formance, so eminently useful to the nemertean, was purelv reflex, how much chemotactic, and how much instinctive r" And who will assert positively that there was no trace of consciousness, even of intelligence, in it? An extremely interesting line of inquiry is suggested by cases of "trial and error" like this where at one extreme the "errors" are not much less numerous than the successes, and, at the other extreme, are cases in which the errors are re- duced almost to nil. A type case of this last would be the poise-and-spring of a cat after its prey. With little doubt a closely graded series could be made out running through from one extreme to the other. A cardinal interest in the inquiry would be as to the extent to which the simple reflex, tropistic reflex, instinct, and intelligence figure in the dif- ferent grades. Would it not turn out that the gradual diminution of error through the series would be, generally speaking, concomitant with the increase of intelligence.? I suspect so. Tendency of Suhrational Activities to Excessiven-ess The fourth and last certainty about reflex and instinc- tive activities to receive attention is their tendency to ex- cessiveness — their way of going beyond what is necessary or even really safe for the welfare of the organism. Although from several points of view this is one of the most impor- tant aspects of the whole subject, it has received surpris- ingly little attention, especially by the modern school of ex- perimental zoology. Probably every one who has observed animals widely and Organic Connection Between Physical and Psychical 257 thoughtfully has been impressed with the exuberance of their performances. That they are ever wont to overdo thlnirs, even operations which are wlien done in measured fashion absolutely essential to their existence, is matter of common knowledge. Holmes has some comments under this head which may fitly introduce our presentation. "With all their wonderful adaptiveness instincts are far from ideallv per- fect. Much of Mark Twain's remarks on the futility and imbecility, the wasted effort and labor at cross purj)oses shown in the behavior of ants may easily be verified by anv observer." ^^ A common form taken by excessiveness of action is repe- tition. Very many, perhaps all, animals are notorious re- peaters. A few out of the many available instances will suffice to fix the phenomenon in mind. Some time ago a small whale (probably a half-grown Humpback, Megapfera versabilis) came near shore at La Jolla, California, and re- mained in the same small area for days. While there it went through a particular set of movements known to whal- ers as "breaching" scores of times, each set being exactly, so far as one could see from the shore, like every other set. The performance consisted, in this case, of a leap out of the water, which carried the body clear of the surface of the sea, the direction of emergence being probably thirty degrees from the perpendicular. During the ascent the ani- mal turned with a characteristic twist to the left and came down on its head and left side wdth a great splash. Once back in the ocean the creature reversed the course it was going when making the leap, returned to some distance from where it had emerged, reversed its course again, and re- peated the leap identically, to all appearances, even as to the spot of emergence and direction of travel. Wliy so many times the same performance in the same spot? Tliat is the problem which concerns us here. Even though we conceive it to be somehow adaptive — connected in some in- 258 The Unity of the Organism direct way possibly with feeding or reproduction or migra- tion or some other vital function — the question still remains, why so much of it? And to this no probable or even ra- tional answer is forthcoming from the standpoint of adapta- tion and utility, taking these terms in their usual meaning. Here is another case from the mammalia, the possible adaptive significance of which is still more remote, if any- thing, than that of the behavior of the whale. Many indi- vidual mice of the genus Peromyscus being used by Doctor Sumner and Mr. Collins in their researches on heredity and environmental influence at the Scripps Institution take to throwing back summersaults in their cages. The more com- mon performance consists in a run along the floor of the wooden cage and up its side to near the top, then a quick, strong jump backward clear across the cage, the feet being uppermost during the first part of the leap but coming to rights again by the time the landing is made. Here again the question of why the mice do this seemingly useless thing is not so interesting for the present discussion as that of why they do it so much. The high flight of some species of birds, the great eleva- tions being reached by long, regular upward spirals, would appear to come under the head of non-adaptive, superfluous action. The sand-hill crane, Grus Tuexicana, may be taken as an instance of a bird given to this habit. Surely such flights by this species can have nothing to do with food- getting, since in the excursions the bird is going directly away from, instead of into, the region where its ^ food abounds. It eats snakes, frogs and other creeping animals, and various seeds and roots. Nor is there any evidence that the flights are concerned with the mating function, nor yet with migration, though one might possibly imagine that while on the excursions the birds learn, after a fashion, the topography of the surrounding regions. The high-diving and booming of the night-hawk, Cordeiles Organic Connection Between Physical and Psychical 2r)9 viryinianus, repeated time after time in the early evening and occasionally in midday when an aijproaching storm cools the air, would seem to be another j)erformance of the non- adaptive sort. The suggestion that this is a courtship af- fair can hardly stand, in view of the fact that at least as often as otherwise the birds which do it are entirely alone. Nor can one see how so extensive and swift a dive, with so much noise, can be advantageous for the capture of flying insects. And reflect on the quantity of movement of many ani- mals. Can any one believe that mammals and lizards run, birds and insects fly, and fishes swim just exactly so much as and no more than, they must in order to survive.^ Would it be contended that the Golden Plover, to take»a well known case of extensive migration, would certainly succumb in the struggle for existence on anything less than a journey from the high latitudes of the northern hemisphere well into the southern hemisphere and back, each year? There is a vast difference between a necessity for migration to some ex- tent and a necessity for migration of a particular quantity. One of the great weaknesses of the natural selection theory has been, I am very sure, its slight regard for quantity ; quantity of need, quantity of performance, quantity of benefit. These examples serve to illustrate the fact that among the higher animals at least, much muscular activity occurs which is not at all, or only partly, adaptive. But by far the more common occurrence of excessive activity is in connec- tion with behavior which is more or less obviously adap- tive. "A o-ood thill": carried to excess," in the familiar phrase, expresses well what is in mind here. This excessiveness of adaptive activity is naturally more easily recoo-nized in animals which are most easilv observed and most active generally. Thus it Is from birds and in- sects that examples can be most readily drawn. 260 The Unity of the Organism Let the current view be accepted that the song of pas- serine birds is associated adaptivelj with the mating func- tion. Even so, no one who has given careful attention to the matter can have failed to recognize that with many species much more singing is done than actual pairing and breeding call for. I have kept almost daily notes for sev- eral years on the singing of the Western Meadow Lark, Sternella magna neglect a, in the vicinity of La Jolla. The birds are resident the whole year through, and as they come familiarly around my home and laboratory, the observations can be quite full. Although the breeding time is restricted to late February, March, April, and sometimes May, there is not a month in the year when songs may not be heard, most of the time in full volume. Significantly, I believe, the song is at its ebb during some weeks just before the nesting period begins. Nor does the singing of the males seem to be connected in any close way with mating. The birds do not pair off closely and permanently, even for the breeding season. Most of the singing, which occurs cliiefly in the morning and early forenoon and again toward evening, is done while the singer is, more commonly than otherwise, quite alone on some telephone pole or wire. And the mode of singing does not change at all when mating begins. An- other interesting fact about the singing of this species is the considerable range of temperature and light conditions over which the song is invariable, so far as these factors are concerned. The song may be as full and frequent on cloudy, misty mornings as on sunny ones ; and over a con- siderable range of temperature the song is quite independent of the particular degree marked by the thermometer. While the song habits of this bird are undoubtedly some- what exceptional in their looseness of correlation with mat- ing and with environmental conditions, certain it is that much this sort of thing is observable with several resident species which I have observed. The house finch, Carpodacus Organic Conjiection Between Pliysical and Psychical 261 Mexicanus, and the Califurnia tuwlicc, Pipilo fimciis, may be specially mentioned in tills connection. The fact that do- mesticated song birds, like the canary, may be brouglit to sing almost perpetually is only an extreme manifestation of tendency among song birds to sing in excess of any strict utility of song. Think of tlie monotonous repetition in the croaking of frogs, the chirping of crickets, the stridulations of cicadas, and so on ! I have counted more than five hundred con- secutive chirps of a cricket in about half an hour, with only a little variation as to notes or intervals. And tliis is surely a very moderate example of what actually occurs — as any one can easily convince himself by listening and count- ing almost any still night, almost anywhere where crickets live. Probably the chirping of crickets is employed in mat- ing. Very well. But are the thousands of cliirps uttered by a given individual each niglit for many nights, the small- est number upon which the species can survive .^^ Even ask- ing of the question reveals the monstrosity of a theory that would necessitate an affirmative answer to it — as strict ad- herence to the natural selectionist meaning of utility un- doubtedly would. In place of bringing forward additional instances, which could easily be done, to show that vocal sounds and bodily performances of various sorts more or less obviously con- nected with mating among higher animals are produced in excess of what the strict application of the rule of physio- logical economy would dictate, I shall do no more than util- ize the conclusions of two investigators who seem specially qualified to speak on the subject, and assume that these con- clusions would receive the sanction of all zoologists who have given serious attention to the matter and have formed their judgments unbiased in favor of any explanatory theory. The first of these investigators is W. II. Hudson, who represents a period a little antecedent to the present spc- 262 The Unity of the Organism cially critical experimental era. I quote from his well- known The Naturalist in La Plata, published in 1892: "I wish now to put this question : What relation that we can see or imagine to the passion of love and the business of courtship have these dancing and vocal performances in nine cases out of ten? In such cases, for instance, as that of the scissor-tail tyrant-bird, and its pyrotechnic evening displays, when a number of couples leave their nests, con- taining eggs and young, to join in a wild aerial dance; the mad exhibitions of ypecahas and ibises, and the jacanas' beautiful display of grouped wings ; the triplet dances of the spur-winged lapwing, to perform which two birds already mated are compelled to call in a third to complete the set; the harmonious duets of the oven-birds, and the duets and choruses of nearly all the wood-hewers, and the wing-slap- ping aerial displays of the whistling widgeons ; will it be seriously contended that the female of this species makes choice of the male able to administer the most vigorous and artistic slaps? . . . There are many species in which the male, singly or with others, practises antics or sings during the love-season before the female; and when all such cases, or rather those which are most striking and bizarre, are brought together, and when it is gratuitously asserted that the females do choose the males that show off in the best manner or that sing best, a case for sexual selection seems to be made out. How unfair the argument is, based on these carefully selected cases gathered from all regions of the globe, and often not properly reported, is seen when we turn from the book to Nature, and closely consider the habits and actions of all the species inhabiting any one district. We see then that such cases as those described and made so much of in the 'Descent of Man,' and cases like those mentioned in this chapter, are not essentially different in character, but are manifestations of one instinct, which appears to be almost universal among the higher animals. The explana- Organic Connection Between 'Physical and PsycliicaJ 2(53 tion I Ih'ivc to oft'i'j- lios very iiiiicli on the .surface, . . . We see that tlie inferior animals, wlien the conditions of life are favorable, are subject to periodical fits of gladness, affecting them powerfully, and standing out in vivid contrast to their ordinary tem])er. And we know what this fecliiiiJ- is — this periodic intense elation which even civilized man occasionallv experiences wheji in perfect health, more especially when young. There are moments when he is mad with joy, when he cannot keep still, when his impulse is to sing and shout aloud and laugh at nothing, to run and leap and exert him- self in some extravagant way." ^^ The reader is asked to note what Hudson says about pick- ing out such evidence as will help the case for sexual selec- tion, and saying nothing about evidence which will not hel]) it. Beyond question the dogma of natural selection, espe- cially the Weismannian perversion of it, has flourished largely on this sort of thing. Nor has natural selection alone among biological theories had the benefit of assorted evi- dence. Indeed the whole elementalistic mode of interpret- ing living nature may be characterized as one whose doc- trines depend largely upon "special privilege," to adopt a phrase lately much used in the economic world, as to evi- dence for their support. The other investigator upon whom we draw is Prof. Julian S. Huxley, whose work is that of a field zoologist imbued with the exacting spirit of the present day. Huxley's stud- ies are devoted to the mating habits of birds, so there can be no question that the activities he describes are intimately connected with reproduction. Of thi- numerous s})ecies dealt with in the paper now before us, we notice first the Great Crested Grebe. It is highly significant that in this species mating takes place before the so-called courtship performances begin, so this latter process can not be es- sential to securing a mate. The female is "courted" after she is got possession of. The courtship activities begin soon 264 The Unity of the Organism after pairing, two entirely different sets of ceremonies be- ing involved in the activities. One of these Huxley calls ceremonies of mutual display, the other, ceremonies of coi- tion. The highly elaborate mutual display performances are fully described but can not be reproduced here. They consist in a variety of body attitudes, head and wing and feather movements, swimmings and divings, and call-notes, the w^hole lasting some minutes. Concerning this prelim- inary operation, Huxley writes : "The most noticeable thing about all these ceremonies is that they are 'self-exhausting' — they do not lead on to any- thing further. Looked at from the physiological point of view, they seem to me to be notliing but 'expressions of emo- tion' : the birds act thus because they are impelled to do so, because they enjoy it. Looked at, on the other hand, from the evolutionary point of view, they seem to have been developed as a bond to keep the pair together." ^^ Following these preliminaries, the ceremonies of coition take place, these being less striking, though characteristic. Speaking of his studies on the mating habits of some of the warblers, and referring to differences of interpretation between himself and W. P. Pycraft, another observer in the same field, Huxley writes : "In this, Mr. Pycraft and myself are, I tliink, agreed; to both of us the 'display' of the male Warbler is nothing but a direct expression of sexual excite- ment, scarcely, if at all, modified by Darwinian Sexual Se- lection — nothing but the way in which nervous disturbance caused by sexual excitement happens to liberate itself. Gen- eral nervous discharge will cause general muscular contrac- tion ; and something approaching this is here seen — rapid hopping, extension and fluttering of the wings, spreading of the tail, bristling up of the fea.thers on head and throat, and utterance of a series of quick sounds. This ex- presses a condition of readiness to pair, and doubtless to the female comes to be a symbol of the act of pairing. Organic Connection Between Physical and Psijchical ^65 Hence, as far as the female is concerned, the act of pairing has come to dej)cnd upon this stimuhis (acting of course on a suitable internal j)hvsiological state). This is no more strange in the bird than it is that in ourselves thoughts and emotions of love well up at the sight of some tangible ob- ject connected with the beloved," ^'^ But it is in the sex function itself that the tendency to overdo manifests itself with greatest force. In fact, the fa- miliar and ominous expression "sexual excesses" as applied to the human animal, indicates very truthfully what is be- fore us. The whole phenomenon of competing and fighting among the males of all higher animals for possession of the females, with its momentous consequences in dozens of ways, may truly be said to rest back on the excessiveness of the sex impulse and instinct. Since as a general rule the males and females of animal species are approximately equal in numbers, pairing off two by two, after the manner of the population of Noah's ark, might occasion but little and mild competition could each male and each female be satisfied with one mate, in accordance with the allotment which the numerical equality would make. And the pertinent question may be raised in passing, would not such a mode of pairing secure the perpetuation of the species quite as well as, pos- sibly better than, the method which is so largely in vogue .'^ Highly suggestive seems to me in this connection, observa- tions I have recently been able to make on the mating hab- its of one of the California "surf perches" {Cymatogastcr aggregatus). This is one of the numerous viviparous bony fishes peculiar to our coast. The species under attention lives quite normally, as far as one can see, in the aquaria of the Scripps Institution; so what may be assumed to be its typical habits can be observed continuously. Strict monogamy appears to prevail in the species. At least this is true with the specimens — three males and four females under observation, and so far as a particular breed- 266 The Unit!/ of the Organism ing period is concerned. Each male begins his attentions while his fiancee, so to speak, is heavily gravid from the pre- vious mating (when and how accomplished we unfortunately know nothing about beyond the fact that it must have been before the individuals under observation were brought to the aquarium from the sea, about six weeks before the mat- ing began.) In the case of one pair, the amours of the male continued more than two weeks, the first few days of which were before the family of young began to be born, the period of parturition extending over three days. Although there was no indication on the part of the other males of inten- tions or even desires toward the spouse (as she may now be called) of this male, he was quite pugnacious, directing his seemingly unnecessary operations against the other females as well as against the other males. It should be said, how- ever, that his antipathies were considerably greater against the males than against the other females. The other two males took partners after much the same fashion ; but since both of these were somewhat smaller, and fully acknowl- edged the over-lordship of the one singled out in our account, their performances were less clear cut. Specially noteworthy is the character of the amours of the male, which alone or almost alone, seems to take an in- terest in the performance. No contact, or at least only the slightest, of the male with the female was seen though the fish were under observation much of the time. A peculiar downward darting of the male first on one side then on the other of the female, close to her but not quite touching her, was one of the favorite manoeuvers. But various rapid circlings about, up and down, head-on and tail-on, over and under, and in nearly all possible ways, may be witnessed. The full meaning of this monogamic (temporarily so, at least), largely non-tactual type of mating we do not know partly because we have not yet all the facts ; but I suspect Organic Connection Between Physical and Pstjchical 267 it to be important. But this much is clear as to its bear- ing upon the point uppermost in tliis discussion: There is an excessiveness of activity in a variety of ways, particuhirly in the driving of other females, the presence of which in the vicinity of the mate is merely incidental and utterly harm- less. Obviously it is tlie demand, instinctive or organic or both, for more sexual gratification than the natural numerical scheme of the two sexes provides, and the actual necessities of race perpetuation deman.d, wlilch is largely responsible for the contests to secure mates, so characteristic of all higher animals. The bull fur seal must have forty or fifty mates, instead of the one which tlie numerical equality of the two sexes would naturally give him ; hence the fierce com- bats among the males, with the result that a great majority of the whole male population at any one time is forced to remain outside the "harems" during the mating season. And some such eliminative process must occur in all species where the sexes are about equal in numbers, and where promiscuity in pairing is practised. Nor are the injuries and disasters which may result from the driving power of the sex-impulse restricted to compet- ing individuals of the same sex. The mates sought after not infrequently suffer seriously from the excesses of the seek- ing males, the females being usually more passive and hence the more liable to injury in this way. Thus, J. S. Huxley has lately told of the exliaustion and actual death of the female mallard duck from being repeatedly "tread" by the males, the same and different individual males participating in the strangely destructive performance. Finally, the individual itself is not safe from self-injury through its own sex impulses. Some of the forms which this sort of thing may take in tlie human species are too famil- iar, too disastrous and too repugnant to need illustration in proof of their reality. That they occur also more or less 268 The Unity of the Organism among animals is well known to all who have had consid- erable experience with domestic animals. Excessive activity in connection with the alimentary func- tion must now be glanced at. That there is no nice quanti- tative balance between the food necessities of the animal and the food gathering instincts and impulses and efforts on the basis of the principle of natural economy and parsimony, is shown conclusively it would seem by many animals which have the storing habit. The honey bee is an example of this among insects. Given a sufficient supply of flowers to work on, in the wild state these bees seem always to store away more food material than they consume. The extent of their honey-making is limited rather by the raw material available and by their own restricted phys- ical powers than by their nutritional needs. This is the im- pression I have from my observations on wild and tame bees and I find it to coincide with that of other naturalists whose opportunity for obsei-Aang wild bees has been much greater than mine. For example my esteemed naturalist friend, Mr. Frank Stephens of San Diego, California, reminds me that the view is confirmed by the fact that in "bee trees" a por- tion of the comb containing honey is not infrequently black and shows signs of being old. Darwin made quite a point, it may be recalled, of the economy in some aspects of the bee's work. "The comb of the hive-bee," he says, "as far as we can see, is absolutely perfect in economising labour and wax." {Cell-Making In- stinct of the Hive-Bee, in The Origin of Species.) ^* But a thoroughly economic adjustment between different parts of a given complicated operation, and economy of the opera- tion as a whole, are very different. As an instance of excessive repetition in the food-getting activities among the insects, the following from Fabre may be taken as fairly typical. A solitary wasp of the genus Sphex captures and slays a locust, but instead of using it Organic Connection Between Physical and Psychical 269 at once for food, or of taking it directly into her home, she sometimes leaves it on the road, and nins to her home, even though this is threatened by no danger. Then after a time she returns to the game. Tliis going-and-coming may be performed repeatedly before the carcass is finally taken into the dwelling. If by chance the game is removed during the absence of the wasp, the wasp returns to the spot where her load was left, but, not finding it, she, nevertheless, keeps up the going-and-coming for some time. The first back-and- forth journey from game to dwelling is explicable, Fabre shows. "But what is the use of the other visits, repeated so speedily one after another.'"' Fabre inquires.^ ^ Something like this almost every one must have seen, who has watched in- sects at all. I am quite certain that the acorn storing habit of the California woodpecker, Melanerpes formicivorus bairdi, is quite beyond any use the bird makes of the acorns. In the first place, despite much discussion of the question whether the acorns are used at all, and if so how, the case is by no means clear. But the point I particularly wish to make is that whatever use, if any, the birds make of the acorns, whether as food directly or as culture media for worms or insects, these in turn to be eaten by the birds, they store up many more than they utilize. This seems to me highly prob- able from the fact, which I have ascertained by numerous examinations at different places and times, that many holes contain dried up and wasted acorns which show no signs of having been picked at or otherwise moved after they were inserted into the holes. Furthermore, the great extent of the hole-drilling and filling in itself seems to exceed the bounds of necessity, especially in view of the certainty that the bird's chief food supply is from quite another source. A pine log fifty feet long and one hundred thirty-six inches in girth at the middle, which I found in the San Jacinto Moun- tains, contained on a fairly careful estimate 31,800 holes. 270 The Unity of the Organism many of them containing acorns. But even were it certain that the acorns are utilized in any manner and to some extent in connection with the feeding function, there are still other evidences than that just ad- duced of the imperfect and excessive operation of the acorn- storing instinct. As is well- known, the bird sometimes ex- tends its drilling operations to wooden buildings to the ex- tent of making itself a great nuisance. I have seen a case where the birds had pierced the rustic of an uninhabited house, so that when the acorns were inserted, instead of filling the puncture as they would fill holes in a tree, they would drop down into the space between the rustic and the inner wall. Apparently the failure to stop the hole, and failure also to perceive why, or to recognize that the hole could not thus be stopped, "fooled" the birds into putting one acorn after another into the same hole, endlessly almost, judging by the great quantity of nuts piled up at the bot- tom of the space. While the storing habit of the California woodpecker is undoubtedly exceptional as to extent, it is by no means wholly unique. At least one species of blue- jay (Cyanocitta cristata) has much the same habit, in the opinion of most ornithologists who have studied the habits of the bird. An experienced naturalist, E. H. Forbush, has recently said concerning Mark Twain's "Baker's Blue Jay Yarn," in A Tramp Abroad, "All of this is not merely amusing; it is good ornithology in so far as it reports the way a Jay acts." ^^ This story, it may be said for the benefit of any reader so unfortunate as not to know it, turns upon the performance of a jay similar to that narrated above about the California woodpecker, the acorns, and the old house. The habit of the shrikes (genus Lanius) of impaling their victims and leaving them, almost certainly operates more or less independently of, and often in excess of, the food re- quirements of the birds. ''My observations," says Forbush, Organic Connection Bet-ween Physical and Psijchical 5^71 "have led nie to believe that it rarely returns to eat what it has thus cached, unless driven to do so by liunfrer resulting from adverse fortunes of tlie chase." ^'^ Nor is tliere much if any question that something of the same sort occurs among- mammals wliich have the food stor- ing liabit. p]. T. Seton quotes the following from Dr. John Wriglit concerning the big eastern chipmunk {Tamias strin- tus grisens) : "It is a most provident little creature, con- tinuing to add to its winter store, if food is abundant, until driven in by the severity of the frost. Indeed, it seems not to know when it has enough, if we may judge by the surplus left in the spring, being sometimes a peck of corn or nuts for a single squirrel." ^^ There are many other statements by the best authorities, especially concerning numerous spe- cies of mice, which strongly suggest a like superabundance of storing activities. But for the rest I w^ill mention a case that has come to my own notice. I am indebted to jMr. Frank Stephens for information about and the opportunity to witness to some extent for myself the operations of the storing instinct and feeding habits of the Antelope Ground-Squirrel {Amnios pcrinophi- lus leucurus). This chipmunk-like little squirrel proves to be so readily domesticable that it becomes almost as famihar a household member, at least for ]\Ir. Stephens' household, as a domestic cat. Altliougli an account of the habits of the single individual in Mr. Stephens' possession can not yet be told fully by a long ways, a few points of much interest for the present discussion are ])ositive enough. In tlie first ])lace the genuinely instinctive character of the storing habit is establislied by the fact tliat althougli the specimen under observation was taken soon after birth, and has lived all its life in complete isolation from parents and all its kind and has been furnished artifii-ially with an abundance of food, its storing operations are carried o?i constantly and almost as perfectly, so far as one can .jiulgv. 272 The Unity of the Organism as though it were living in the natural state. This fact in itself is evidence that the instinct is not determined solely by immediate needs of the individual. But much more convincing evidence furnished by this case to this effect is in the particular way the instinct works. For example, this species possesses cheek pouches for carrying food as do so many rodents which have the storing habit. When nuts, grain, etc., are presented to the animal she very rarely eats them immediately even though manifestly hungry, but carries them away to some distance, one at a time ; going back and forth and placing the articles in her two pouches till these are quite full. And these little pre-storage journeys, as they may be called, are often definite in character. At any given time they end at nearly the same spot, and the animal takes nearly the same position while the article is being pre- pared for and inserted into the pouches. This is clearly the typical procedure in filling the pouches, though it is varied considerably from time to time. As to what follows the pouch-filling there is considerable variation — noraially so it appears. In case the animal is hungry she may quietly extract the nuts from the pouches and eat them. Or she may run about for some time with her cheeks bulging full. Or she may take her load off some- where and lay it away either in some cache previously es- tablished or in a new one. The cache may be in a bed of sand if this is at hand ; or it may be in or under some old garment or piece of cloth or paper which the surroundings may present. An especially interesting fact noticed by Mr. Stephens is the tendency shown on the part of this squirrel to carry the articles to as distant a place from where it gets them as can well be reached. On the whole there is no doubt that we have here a var- iedly illustrative example of activity over and above need in the operation of an instinct. Organic Connection Between Physical and Psjjchical ^Ti) This bare touch, so far as instances are concerned, of overactivity in connection with reflexes, and especially with instincts wliich are on tlie wliole useful, leads naturally to the great field of animal play. Space limitations ])rohibit us from taking more than a bird's eye view of this field. Fortunately, however, even such a view can be quite effective for our purpose because of the well-known work of Karl Groos, The Ploy of Animals. Our sole purpose here, as in the rest of this discussion, is to answer the question whether animals do or do not carry their activities which on the whole are fundamental to their existence be3'ond what is necessary for their own individual requirements. With Groos's explanatory theory of play we are concerned only so far as it involves the question of fact upon which our present interest centers. That most if not all animal activ- ity which can rightfully be called y)lay, and which is not intelligent, is instinctive, we believe Groos has conclusively shown. The explanation adopted by Spencer and others that play is the useless imitation by young animals of useful activities performed by their seniors, the imitative acts be- ing useless because merely the overflow of "surplus energy," is certainly inadequate, as Groos has insisted. That animals constantly go through perfomiances playfully which they have had no chance to see or to have otherwise impressed upon them from without, is as certain as that they constantly perform useful acts in this way. It consequently results that a source of energy for play, that is, for actions which are not immediately essential to the existence of the organism, must be an endowment of tin organism no less certainly than that a source of energy mu>f exist for actions which are essential to its existence. So Groos's statement: "A condition of sur})lus energy still ap- pears as the conditio sin^ qua noii that pennits the force of the instincts to be so augmented that finally, when a real occasion for their use is wanting, they form their own mo- 274 Tine Unity of the Organism tive, and so permit indulgence in merely sportive acts," ^^ becomes a statement of fact if by "surplus energy" we understand energy available for, and upon occasion used for, acts wliich are not indispensable to the existence of the in- dividual. The quantity and generality of play performed by animals may be taken as one important measure of the extent of the energy possessed over and above what is essential for their normal individual existences, and this without reference to whether or not the play may be useful as a preparation for future essential activities, or for recreation only. The fact can hardly.be too much insisted upon that ulterior useful- ness of the organism's acts, whether to the species generally, to offspring, or to the individual's own future, cannot pos- sibh^ be a sufficient explanation of the energy immediately re- quired for the act itself. Even though an animal does noth- ing whatever except by reason of its hereditary endowments, or in the interest of its offspring; and though the real pur- pose of much that it does looks to its own future, it must nevertheless continue to eat, digest and assimilate, and breathe. The subdivision of biology which has come to be known as physiology has for its distinctive task exactly that of studying the present activities of the organism. With the organism's past, whether individual or racial, and with its future, whether individual or racial, physiology can be concerned only indirectly. Summary of Orgcmismal Character of All Suhrational Psychic Life Having now examined broadly though far from exhaus- tively the psychic life of the animal in each of its most ob- vious phases, the highest rational phase, the emotional phase, the instinctive phase, and the reflex phase (in which tropisms are included) for purely descriptive and classificatory pur- Organic Connection Between Phi/sical and Psijchical 275 poses, let us briefly summarize wlint we have learned. In each phase we have found the oryunism, living, whole and normal, indispensable to a comprehension of the phe- nomena examined. Or, expressed in a different way, we have found it possible in each phase to reach only a very imperfect understanding of the phenomena by referring tliem to the elements which can be discovered in them. For example, the theory of association of ideas is inadequate to explain ra- tional life, in such manifestations as apperception and mental initiative and creativeness. In the emotional phase, in such emotions as fear, rage and sex passion, not only does cursory observation recognize the involvement of a large part of the organism, but physi- ological investigation is able greatly to extend our recogni- tion of this involvement by showing how the nervous system in its cerebro-spinal and its autonomic divisions, the cir- culatory, the alimentary, and the internal-secretory sys- tems, are essentially and reciprocally involved. As to the organismal character of psychic life in the phase of instinct, it suffices to recall that one of the most widely accepted criteria for differentiating instinctive from reflex activities is that the former involve the organism as a unity, a whole, while reflexes, according to this criterion, pertain only to limited portions of the organism. '*An instinct is a more or less complicated activity manifested by an organism which is acting, first, as a whole rather than as a part." -"^ To this statement of the matter may be added that when the instinctive act is in the interest of the indi- vidual performing it, the act is not only by but for the in- dividual as a whole. As to the reflex phase (if that is to be reckoned as psy- chic) the organismal nature of tropisms has liad so large a place in our discussion that surely no more nerd l)e done in this summary than to remind the reader of our discussion of tropisms. And even reflexes of a simpler fDiifi than tlie 276 The Unity of the Organism tropisms — indeed the abstract conception of the "simple reflex," though not, perhaps, involving the conception of the organism as a whole, yet is not comprehensible on elemen- talistic principles, as our examination of Sherrington's in- vestigations revealed. And such phenomena as those of the spreading and compounding of reflexes are quite incompre- hensible except on the organismal principle, even though the whole organism may not be involved, observably at least, in particular reflex acts. Specificity of Siihrational Psychic Life The concluding section of this descriptive chapter on psychic integratedness must be devoted to the specificity, not to say individualit}^, of animal behavior in all its phases. The vast body of trustworthy detailed knowledge now in our possession justifies, I am quite sure, the following general- ized statement under this head: It is exactly on the psychic side of animal life, psychic being taken in the broadest sense, that animals are most differentiated from one another, both as to individuals and as to species. Taxonomic zoology is based almost entirely on structural attributes of animals. This results from reasons that are obvious, speaking generally, and constitutes a justification of the fact from a practical standpoint. Nevertheless the purely practical advantages of the classificatory systems as they have been built up have been, and are, gained at the expense of several rather serious disadvantages. One of these is, as advance of knowledge leads us to realize, that our well-nigh exclusive attention to structural diff^erences and likenesses has tended strongly to divert attention from func- tional differences and likenesses. It is of fundamental impor- tance for a truly comprehensive science of organic beings, that is, for a philosophical biology, to regard our synoptic classifications not as a final result of knowledge-getting, but Organic Connection Between Physical and Psijchical 277 rather as a life-sized sketch, as one may say, of the whole living world, to facilitate the gigantic task of completing the picture through the cooperation of numberless artists, the completion to be accomplished by filling in the sketcii with the entire round of attributes, structural and func- tional, presented by the natural lives of organisms. I have dwelt somewhat at length on this matter elsewhere,* and can refer to it here only as a background for what I wish to say about psychical specificity. Two extracts must suffice. "No biological phenomenon is adequately interpreted or dealt with experimentally, until it has been considered with reference to the place that the organism to which it pertains holds in the system of classi- fication." And further: "What I affirm is that the inductive evidence has now gone so far toward proving every sharply differentiated species to contain some differentia in all the main provinces of their structure and function, that to as- sume the absence of such differentia in any given case is unwarranted." ^^ I want to utilize these earlier general statements about organic specificity, as a basis on which to rest a generaliza- tion concerning the specificity of psychic attributes. So enormous is the observational data available for illustration here, that in lieu of presenting any of them I am going to state in a wholly dogmatic fashion the generalization toward which we are certainly being led by modern crucial researches on animal behavior. Let us imagine ourselves possessed of an approximately exhaustive descriptive knowledge of the be- havior of the whole animal world, tliis knowledge Ix'ing, liow- ever, unaccompanied by any knowledge whatever of the cor- poreal nature of the animals. This behavior-knowledge would fall naturally into categories larger and smaller, the * The Place of Description, Definiti