Physiological Foundations of Behavior

ot vrerepl cheb ly v A hag TO pt ts aS Spe he er et Peay na havi ep wih! The work of recent years on the problems of heredity and genetics has modified in many ways our conceptions of the mechanisms of in- _heritance, but has to a large extent ignored the problem of the mechanisms by which particular hereditary potentialities are realized as characteristics of particular individuals. Since knowledge of heredity and its mechanisms can be attained only through the study of individuals, any advance in our knowledge of the individual and - its mechanisms must necessarily contribute in one way or another to our knowledge of heredity.

If the organism and the “germ plasm” are physico-chemical systems, the development of an individual organism in any specific protoplasm involves an orderly sequence of physiological activities and for such activities relations ‘between the protoplasm and its environment are necessary. In recent years students of heredity have given but little attention to the rdle played by reaction to environ- ‘mental factors in the realization of hereditary potentialities in an individual organism. If we admit that such reaction is behavior in the broad sense, this question is the question of the significance of behavior in individual development. And if behavior in this sense plays any essential part in individual development, such behavior and its effects at any given stage must be concerned in determining the behavior of later stages.

This book is a consideration of the general physiological features of individual pattern from the viewpoint of behavior, that is, of reaction to environment. The question underlying the whole discussion is: given the hereditary potentialities of a particular species, how are certain of these potentialities realized as characteristics of an individual of the species? Current theories of heredity leave us, I believe, no other basis than relation and reaction to environment on which to formulate an answer in physico-chemical terms to this question. The conception of the early stages of the process by which hereditary potentialities become real physiological and morphological features of an individual which is developed in this book is based on many different lines of evidence and throws light on many problems of individual development. Doubtless the advance of our knowl-

edge of the physiology of protoplasms will modify in many ways the ~ terms in which the conception is stated, but that individual development must be interpreted in terms of reaction to environment of a specific protoplasm cannot, I believe, be denied without ignoring many facts. The book is a further development of the views advanced in Chapter IX of “Senescence and Rejuvenescence,” “Individuality in Or- ganisms”’ and ‘‘The Origin and Development of the Nervous System.” Chapters I-VI are concerned with a general discussion of organismic pattern and integration. Chapters VII-X comprise a new presentation of the evidence for the conception of physiological or metabolic gradients. This presentation is made necessary by the progress of investigation since the publication of “Individuality in Organisms” in 1915. Chapters XI-XV are concerned with various aspects of physiological integration in the individual in their relation to environment. And finally in Chapters XVI and XVII the idea is developed that social integration as a reaction process among human beings is in many respects very similar to physiological integration in the development of the individual.

The appearance of the book at the present time and in the present form is due in some measure to the suggestion of my colleague Dr. C, J. Herrick that we should collaborate in some way in a discussion of the foundations of behavior in organisms. This collaboration has turned out to be the writing of two books, this one concerned with the general physiological foundations of behavior, the other, with the neurological foundations and mechanisms of behavior in animals. The two books are primarily concerned with different aspects of the problem of individual behavior and in that respect are in large measure independent and there has been no sacrifice of personal views for the sake of unity. N evertheless, they are conceived, and it is hoped, may be accepted as a collaborative study of some of the fundamental factors in organismic behavior.

To many of my colleagues and co-workers I am deeply indebted for suggestions and criticisms and the use of data and figures: first of all to Dr. C. J. Herrick for repeated reading of the manuscript and for many suggestions and criticisms; to Dr. W. C. Allee, Dr. A. W. Bellamy and Dr. L. H. Hyman for reading and criticism of the manuseript; to Mr. J. N. Gowanloch for permission to make use of unpublished data and figures. I take this opportunity of expressing my appreciation of the work of the artist, Mr. Kenji Toda, in the redrawing of a number of figures.

For permission to reproduce published and copyrighted figures acknowledgments are due to the following publishers and authors: Messrs. A. and C. Black; The Carnegie Institution of Washington; The Columbia University Press; Henry Holt and Co.; The University of Chicago Press; Dr. A. W. Bellamy, Dr. Otto Glaser, Dr. R. G. Harrison, and Dr. H. S. Jennings. The sources of all figures reproduced from the work of other authors are indicated in the legends.

Protoplasms. Organismic Pattern. Relations of Protoplasms and Organisms to Environment. Tur ORGANISM AS A WHOLE: HisTorICAL AND CRITICAL... ... The Réle of the Elementary Organism. Predetermination versus Epigenesis. Vitalism. Conclusion. Tue GENERAL CHARACTERISTICS OF ORGANISMIC PATTERN.... The Relation of Dominance and Subordination. The Spatial and Morphological Factors in Organismic Pattern. Organismic Pattern and Individual Organisms. Transportative Correlation. Dynamic Correlation. The Problem of the Origin of Differentiation.

OEMUNDIVADUIAL Se otic rare ite tetera che sre pa rtretecs Dominance and Subordination in Reaction. Surface-interior Pattern. Polar Pattern. Bilaterality. Alteration Tyr PHYSIOLOGICAL GRADIENTS. «0.0.0 2s reece tenets The Evidence for the Existence of Physiological Gradients. The Conclusions from the Evidence. Surface-interior Pattern and Cell Pattern in Relation to Physiological Gradients. Tur PHYSIOLOGICAL GRADIENTS IN RELATION TO LOCALIZATION AND DIFFERENTIATION... 000s cece sess eee e eens

The Gradients as a Possible Basis of Localization and Differentiation. Data of Observation and Experiment. Lo- calization and Differentiation of the Nervous System in Relation to the Physiological Gradients. Conclusion. THe ORIGIN OF THE PHYSIOLOGICAL GRADIBNT Sas) era cuiercn ns Determination of Physiological Gradients by Light. De- termination of Gradients by Electricity. Determination of Gradients by Gravity. New Gradients in Regulatory Development and Agamic Reproduction. The Origin of the Gradients in Eggs. The Origin of Surface-interior Pattern. The Origin of New Gradients in Relation to Heredity.

PuHyYSIOLOGICAL DOMINANCE AND PHYSIOLOGICAL ISOLATION... . Physiological Dominance and Subordination in Plants. Physiological Dominance and Subordination in Animals. Physiological Independence of Parts and Organs in Relation to Dominance. Mosaic Development. The Dominant Re- gion as a Pacemaker. Physiological Isolation. Dichotomy, Twinning and Axial Reduplication in Relation to Physiological Isolation. The Limit of Individual Size. The Formation and Isolation of Sex Cells.

The Problem of the Nature of Excitation and Transmission. Primitive and Specialized Excitation Processes. Decrement, Excitation-transmission Gradients and “ All-ornone” Reaction. Excitation and Transmission in Relation to the Behavior of Organisms. Tue INpIvipuaL As A BEHAVIOR PATTERN IN A SPECIFIC PRoTO- PIGASM 2), 5 4:05 « cissva. 45 nlprasy'oy doce a Geen The Occurrence and Significance of Excitation Gradients. The Reversibility of Excitation. The Physiological Axial Gradients in Relation to Excitation-transmission Gradients. Physiological Dominance and Subordination in Relation to Excitation and Transmission. Heredity and the Individual.

Regulatory Activities in General. Regulation and the Normal. Regulation as Equilibration. The Question of the Usefulness of Regulation. Regulation in Development. Excito-motor Behavior as Regulation. Reaction by Trial and Tropism. Reflex Behavior. Regulation in its Historical Aspects. Conclusion. MopirtaBiuity or Excrro-moror BEHAVIOR IN RELATION TO Excito-motor Behavior as the Highest Degree of Organismic Integration. Modifiability and General Organismic Pattern. Modifiability and the Primitive Mechanisms of

Excitation and Transmission. Modifiability in Relation to Differentiation of the Nervous System. Modifiability in Relation to Physiological State. XVI. Tue BrovocicaL FouNDATIONS OF SociaAL INTEGRATION......- 267 Biological Sociology and Sociological Biology. Integration Among Organisms in General. Factors of Social Integration. XVII. THe Course or SoctAt INTEGRATION AND THE Oricin or NEW z (EB VR aE) piste le ok Ole alo blo DAES OU py On ee 4, Sere OOS 288 Primitive Autocracy and Progress Toward Democracy. Social Isolation as a Factor in the Formation of New Groups. Questions of the Future. Conclusion.

IRON EO ais. 6 6 hw bod bub or dodge mobo oud mm oOo DOGS oC 301 Diagrammatic outlines of polar-bilateral plant and animal.. 33 Diagram of a simple reflex arc... -..-- 2. 0s essere te trs 36 Various types of radiate organismic pattern. ......-.-.---- 38 Polar-bilateral patterns and spiral modifications........-.- 39 Diagram illustrating the basis of transportative correlation.. 46 Diagram illustrating the basis of transmissive correlation... 51 Reactions and forms of Amaba.:.........beeee beer r eee 59 Early development of the Blea, MUCUS. cic he cn oe Ta 60 Reaction of conifer to removal of growing ti kee. oa eae 62 Development of hydroid from planula of Phialidium......- 63 Oral area of a crinoid, Antedon, with bases of arms......-- 64 Diagrams showing different patterns with respect to use of

FOR Acetourde cE eA IO 0 ces radiata, baleen 65 A polar-bilateral echinoid, Brissopsis lyrifera, in locomotion. 66 A holothurian, Pentacta frondosa, ventral aspect.......---- 67 Spiral path of Paramecium. ....-.-ssseerrs rcs s ttt 71 Spiral path of rotifer, Diurella tigris . .. 0.2. see tees 71 Susceptibility gradients as indicated by the course of disin- Susceptibility gradients in flatworm and annelids........-- 81 Differential inhibition in early development of hydrozoan,

Pr TUG ey ne oe ee ee 82 Differential inhibition in larval development of sea urchin, “Lhe POD en Ul lwo ARI ar aS OR 83 Differential acclimation in Arbacia....-.----.+s-esc cerns 84 Differential acceleration in a fish, Macropodus viridi-auratus. . 85 Axial gradients in reduction of KMnO...:..-----+---225°° 88 Pee orcas cells of TOA. caer e ee ne ee en ae 97 Half grown ovarian egg of Sternaspis scutata.........++--> 98 Section of ovarian egg of frog, showing yolk gradient....... 98 Semi-diagrammatic view of ovarian egg of frog, showing a characteristic arrangement of arteries and veins. ....-- 99 Axial section of full grown egg of Chetopterus pergamentaceus before maturation, indicating the structural differentiation of the cytoplasm in relation to the axis........-+--- 99 Lengths of hydranth primordia of stem pieces of Tubularia under various conditions)... .-.-+-.ssssersr ys 102 Size of head, length of prepharyngeal region and position and length of pharynx in reconstitution of Planaria doroto-

Inhibition). eae wee eae Le eee 106 The head forms appearing in the reconstitution of Planaria Cov oloce palais rte, cata aye on ke ak oe 107 Cyclopia in frog, resulting from differential inhibition...... . 108 Kpithelio-muscle cell of hydra.......................:... Lidl Reconstitution in Tubularia............................ 118 Biaxial heads from short pieces of Planaria............__. 119 Experimental determination of new polarity in pieces of stem OL CORMMORDRA oe sce ea ees = ee ener 120 Localization of new axes in sea anemone, Harenactis by localized injury and growth........................... 121 Origin of adventitious buds from epidermal cells of Begonia leaf. dsl, Tthemadeet parte PO cos Oe a ee 122 Multiple adventitious polarities in reconstitution of short pieces of Corymorpha stem.......................... 124 Multiple adventitious polarities in inhibited embryonic development of hydrozoan, Phialidium..............__. 125 Diagrams of reduplicated amphibian legs, showing symmetry relations: .... 2... ...004 mn oon See 128 Reconstitution of pieces of Planaria dorotocephala from different leveld i. 4. ..c .ageten eee a 152 The act of fission in Planaria dorotocephala............... 154 Stenostomum, showing various stages in the formation of chains of"s00ids..1.del a0. eee ee 154 Tubularia, showing physiological isolation of tip of stolon with consequent development of a new hydranth...... 155 Physiological isolation by low temperature block in scarlet- Tunner’ bean i)... “genres eae Ca 157 Dichotomy in liverwort, Melegeria, 62.5%. 4 ae 161 A two-headed Planaria produced by partial longitudinal BPG G, «cia she Rec eee sean 161

Diagrams illustrating dichotomy of a growing region in consequence of growth and flattening in a plane at right angles to the main axis. ..... 0 000), oe eee ee 165 Diagrams of early developmental stages of fish to illustrate dichotomy of anterior end of embryonic area.......... 166 Diagram illustrating transmission without decrement... .... 179 Diagram illustrating transmission with decremént. 4, 188 The avoiding reaction of Paramecvini 9 eee 261

Modification of behavior of Paramecium in capillary tube... 262 Each living thing represents an order and unity of some sort maintaining itself with more or less success in a changing environment. It is the character of this order and unity and its ability to adjust itself to a wide range of changes in its environment which place the living organism in sharp contrast to the rest of the world. We speak of organisms as individuals, meaning that each organism represents -a more or less definite and discrete order and unity, in other words, a pattern, which not only determines its structure and the relations of its parts to each other, but enables it to act as a whole with re- “spect to the world about it. It is this action of the organism as a whole with reference to its environment which constitutes its be- ~ havior as the term is usually employed. The behavior of the organism comprises in fact its reactions and responses to the action of environmental factors upon it. Often, however, we limit the term behavior to those reactions which involve movement, or changes in movement, whether accomplished by specialized locomotor organs as in animals or by growth, changes in turgor, etc., as in plants.

It may be pointed out in passing that while such reactions of organisms constitute a more or less definite reaction group, accomplishing certain results for the organism as a whole, they really constitute only a part of the behavior of organisms. Reaction to environmental factors by change in rate or kind of metabolism or in rate or course of development is just as truly behavior as the motor reaction of an animal to light or the movements of pursuit following the sight of prey by a carnivore. The conception of the organism as a machine which is first constructed and only after completion begins to function, 7. e., to behave as a machine, has been widely held in the past and still has its supporters. According to this conception the earlier stages of development are determined by heredity, that is to say, the factors concerned in the construction of the machine

fare predetermined in the protoplasm, and only at a certain stage of development does function in the proper sense begin (Roux, Weis- | mann. See Chap. XIII). This conception is fundamentally preform- _ istic and fails to take account of the facts of physiology. Actually the organism is not at any stage a closed system, but is functioning and behaving at all times as long as it is alive. Reaction to environment is occurring at all stages of development, though of course the kinds and complexity of reaction differ at different stages according to the mechanisms present. Moreover, such behavior or reaction is itself a factor in development and therefore in the construc- — tion of the behavior mechanisms of later stages. The behavior of | the various developmental stages as well as the specific hereditary constitution of the protoplasm is a factor in determining the behavior of the fully developed organism.

When we analyze the behavior of the organism we find that it consists of the integrated 1 or codrdinated behavior of parts, organs, tissues, cells and protoplasms. From this fact it follows that in the integration of behavior different degrees, scales, or orders of magnitude exist. Different sorts of protoplasmic behavior are integrated into the behavior of cells and different sorts of cellular behavior are integrated into the behavior of multicellular organisms. From this viewpoint the term ‘‘organismic,”’ which has been used elsewhere (Child, ’21 a, p. 3) is as necessary as the term “protoplasmic” and has as definite a meaning. It will be used here, as previously, with reference to those particular degrees of integration, order, unity which constitute the whole organism as contrasted with its constituent parts. Organismic behavior is then behavior of the organism as a whole as distinguished from the behavior of single parts.

1 Ritter (21) maintains that the term “integration” is unsatisfactory for biological purposes because of its implications. His argument is essentially that what we mean biologically by integration is the antithesis of differentiation, and not of disintegration, and he suggests the term ‘‘conferentiation” as the antithesis of differentiation in place of the term ‘integration.’ I am unable at present to appreciate fully the reason for such substitution. According to my point of view, differentation is not biologically the antithesis of integration, but a part, a feature, a phase of it, and disintegration is biologically, as well as otherwise, the antithesis of integration. If, for example, we call the appearance and development of the unity and order which constitute the wholeness of the individual organism a process of integration, differentiation is certainly not physiologically the antithesis of this process, but one aspect of it, and it is certainly first of alla process of “disintegration”? when that individual divides into two or more parts or individuals. The disintegration may not be complete, or it may be followed by new integrations, but it is none the less a disintegration, so far as the original individual is concerned.

_ Behavior is of course not limited to living things. The reactions , to environment of colloids, electrolytes, molecules, ions, atoms, electrons are as truly behavior as the driving of an automobile, or communication by speech or writing. On the other hand, the integration of behavior is not limited by the individual organism. Organisms may be integrated into social groups of various sorts and orders of magnitude and in such groups the behavior of the constituent individuals is more or less integrated into the social behavior .f the group. _ While it is by no means always possible to predict the behavior of | ‘a given kind of organism under given external conditions, there can be ‘no doubt that the character of the behavior is determined by the character of the organism. Organismic behavior presupposes the

existence of an organism, and is dependent upon the mechanisms present in that organism and their pattern of integration. The behavior of an Ameba when exposed to white light of a given intensity is different from that of a starfish and this again from that of an earthworm. The behavior of a green plant under the same conditions differs widely from all of these. Such differences in behavior, whether of different individuals of the same species, of different related species, or of members of widely separated groups have their foundation in differences of some sort in the make-up of these differ-

Some of these differences in behavior, e. g., the characteristic differences between different species, result from differences in the hereditary constitution of the protoplasms and are stable to a high degree. Others, particularly some of the individual differences in the higher animals and to a still greater degree in man, are individually acquired. That is to say, they result from the effects of individual experiences determining the realization of potentialities given in the hereditary mechanisms. For example, many behavior mechanisms are determined in rough outline, so to speak, by hereditary factors reacting to a certain environment, but complete their development only through use: the bird learns to fly, the child to walk. Again, the memory of a past experience alters later behavior: ‘‘the burned child dreads the fire.” In such a case the past experience serves merely as the factor which determines that among the potentialities of action of the mechanisms a certain one shall be realized.

In all these cases, however, it is the organism which is behaving and the constitution of the organism is the primary factor in determining the character of the behavior. In short, the problem of behavior, considered from the general biological viewpoint, involves the problem of the order and unity, the integration which constitutes the organism. We cannot go very far in the biological analysis of organismic behavior without knowledge of the organism which is behaving, and the organism in its relation to behavior appears in two different aspects, the physiological and the historical.

The physiological problem is concerned with the relations between protoplasms and organisms and the external world, the processes concerned in development and maintenance of the different, parts of the organism and the relations between them. Physiology is often defined as the study of function, but life and organisms are functions of protoplasms in a certain sort of external world. Physiology is life viewed as action in protoplasmic substrata, but its task is not completed when it has determined all the different actions in all the different protoplasmic substrata. It must tell us how these actions are related, how they are ordered and integrated into organismic mechanisms and how these mechanisms are integrated into what

_ we call the organism. The problem of physiology is, in fact, the problem of the organism as a physico-chemical action system. Elsewhere (Child,’21 a) I have pointed out that the organism reppresents a physiological pattern of a certain sort. This pattern is primarily the order and unity which constitutes the organism in its simplest terms. As the pattern of a house is different from, and on a larger scale than, the patterns of the various materials or parts which are integrated in the house, so the pattern of the organism