Medical contributions to the study of evolution

Preface

When at the beginning of the Great War the invitation was tendered to me to deliver the time-honoured Croonian Lectures before the Royal College of Physicians of London, it was long months before I could determine my subject. During these months the burden of administrative work in connection with the Canadian Army Medical Service became progressively greater. Research in the laboratory was out of the question. My official duties at that period dealt largely with returns and statistics of invalidism, but soon it became apparent that months, if not years, must elapse before the vast mass of material being collected by the Medical Research Committee at the British Museum would be fully available. Inevitably, therefore, I was led to fall back upon previous studies, and, when still debating, a chance discussion with a leading British biologist convinced me that the time was ripe to bring together and sum up the conclusions regarding Adapta¬ tion which as a student of pathology I had reached gradually in the years preceding the War. I judged from the discussion above referred to that that earlier work was not known to biologists in general. Varied as is his reading and brilliant his memory, this distinguished biologist was evidently wholly ignorant concerning it. It seemed also that it would be serviceable to present the conclusions reached, not so much from the point of view of their medical bearing, as from that of their biological significance, in order that both morphologist and physician might observe the direction in which medical research is surely leading

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THE STUDY OE EVOLUTION

• • •

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us with reference to matters that form the basis of general biology. Hence the Croonian Lectures upon Adaptation and Disease, delivered in June 1917, which form the first part of this volume.

Elsewhere I have dealt with this subject of adaptation for the benefit of the student of medicine ; 1 in dealing with the same subject more from the point of view of the biologist, I had of necessity to refer to and repeat data and deductions employed in my earlier writings. The views here enunciated have been arrived at in orderly sequence from the year 1891 onwards, and it has been difficult to review that sequence with¬ out employing the facts and arguments by which the successive steps were attained.

While making this confession I have at the same time found myself confronted with the difficulty that, in compressing my treatment of the subject into four lectures, much that should have been dealt with in fuller detail, and with greater wealth of examples, has owing to the exigencies of space and time been unavoidably passed over very rapidly. To remedy this, and at the same time to demonstrate that no newly developed doctrine is here taught, but one arrived at and published many years ago, it has seemed advisable to reprint in their entirety 2 certain earlier papers and addresses, all bearing upon adapta¬ tion and tissue modification, which establish and amplify the successive stages of my argument. These are useful as documents in the case. Personally, re-reading them after a lapse of many years, and so with some sense of detachment, they have struck me as to a certain extent entertaining. May their other readers have the same opinion, and obtain a like satisfaction !

It may be held that an apology is due to not a few well-known

1 Notably in the two editions of my Principles of Pathology in 1908 and 1910, but those are works of some thousands of pages ; it is perhaps natural that biologists in general have been deterred from consulting them.

2 Save for slight structural alterations, advisable in converting delivered addresses from the spoken to the printed form. These alterations have been duly noted whenever it has seemed possible that there has been introduced thereby the slightest departure from the sense of the original.

PREFACE

IX

British biologists, many of them for long years my personal friends, on the ground that my Croonian Lectures implied that I regard them all as “ academic.” This, let me hasten to assure them, is very far from being the case. If these lectures be read with reasonable care it will be seen that no such charge is made. I was concerned not to cover the whole ground of modern in¬ vestigations upon the problems of evolution, but to show the bearing of medical research upon matters pertaining thereto. I realize full well that it would have strengthened my case to refer to the work and views of Walter Heape, Professors E. W. MacBride, A. Dendy, and M. Hartog — to mention only those known to me from old association — as confirming my earlier conclusions. I realize this after the event more fully than before, when I had in mind others who from their position and reputation have, rightly or wrongly, been regarded popularly as yet more leading representatives of British biology.

Nor had I in mind American biologists. To have referred to them would have necessitated entrance at length into the Mendelian controversy, for all the morphologists in the States, I am inclined to think, are at the present moment keenly engaged over this matter. Possibly in the future, I shall have a word to say upon the important studies of Castle, Osborne, Whitman, Morgan, Jennings, and others, and the interpretation of the same in the terms of the biophoric concept. In the meantime may I assure my American confreres that I cannot call to mind one of them whom I would accuse of being “ academic.” On the contrary, never has there been a period when American biologists have manifested so great an individual independence, so notable a diversity of opinion, so pronounced a desire to arrive individu¬ ally at the truth, irrespective of the schools and their teachings.

The time indeed has passed when any biologist should justly be labelled as either a Lamarckian or a Darwinian. With abundant material presented to him and freedom of individual judgment, it is scarce possible that the student of to-day should accept unreservedly the teaching of either Lamarck or Darwin.

X

He who is concerned at arriving at the truth is impatient of such labels : it is the truth he seeks, not the confirmation of the views of any one predecessor, however great be the admiration for his work and however large the debt he owes to him.

Yet as regards the ancient controversy, this perhaps should be said, that in so far as between Darwin and Lamarck the essence of the teaching of the latter is that variation is an active process, a reaction on the part of living matter to its environment, the conclusions reached in these pages undoubtedly favour the Lamarckian view. Nevertheless, to accept them does not mean that the principle of natural selection is thereby excluded, or that the two principles are mutually antagonistic, but only that the influence of external forces is the primary process in the produc¬ tion of variation, and that natural selection is secondary, culling out those grades and forms of variation which are least economical and represent the less perfect adaptation on the part of individuals to the conditions in which the family or species finds itself for the time being. Seen thus, evolution, whether what we regard as progressive or as regressive, is the outcome of an active process of continuous adjustment between organisms and their environment.

The survival of the fittest, it will be seen, does not depend upon chance variation. A given environment leads to variation in a particular direction, provided that the change in sur¬ roundings is not so great as to be beyond the adaptive powers of the organism. Where “ chance 55 enters is in the nature of the new environment to which the individual, and the race, may be exposed. To the extent that the individual is unable to control his surroundings, to that extent is the race exposed to chance. It does not appear to have been sufficiently realized hitherto that here essentially it is that chance is operative. Conjugation and amphimixis, it is true, are a cause of individual variation, but from the point of view of the race are distinctly conservative processes, tending to maintain the mean.

When the first of the series of Croonian Lectures was pub-

PREFACE xi listed in the pages of the British Medical Journal , together with an abstract of the second, the biologist whose attitude with reference to adaptation was the origin of those Lectures, saw fit to criticize them more suo. That my readers, with the Lectures before them, may reach their own conclusions regarding the validity of the criticism, it has been deemed proper to publish the correspondence as an Appendix.

It is my pleasant duty to acknowledge my indebtedness to Messrs. Macmillan & Co. for their permission to reprint here the greater portion of a chapter from an article published origin¬ ally in Sir T. Clifford Allbutt’s System of Medicine, and republished subsequently in book form under the title Inflammation ; to Messrs. Lea Brothers & Co. (now Messrs. Lea & Febiger) of Philadelphia, for permission similarly to publish an extract from an article on “ Inheritance and Disease ” contributed to Sir William Osier’s Modern Medicine, to the Harvey Society of New York, and the Editors of International Clinics, British Medical Journal, the Lancet, New York Medical Journal, Mon¬ treal Medical Journal and its successor the Journal of the Canadian Medical Association, the Journal of Pathology and Bacteriology, Medical Chronicle, and Clinical Journal, to reprint articles contributed to their pages. To my friend, Captain R. G. Mathews, C.A.M.C., I am indebted for kindly co-operation in the preparation of the illustrations.

London, August 1917.

Part I

BEING THE CROONIAN LECTURES DELIVERED TO THE ROYAL COLLEGE OF PHYSICIANS, LONDON, JUNE 1917

PAGE

The Basal Problem of Evolution . 3

Adaptation in the Bacteria and the Evolution of the

Infectious Diseases . 15

Adaptation in the Bacteria ( continued ) . . . . 28

Adaptation to Disease-producing Agencies in the Higher

Animals . 45

The Inheritance of Acquired Conditions in the Higher

Animals . 60

• • •

xm

XIV

The Physico-Chemical Basis of Immunity and of Evolution. The Biophoric Concept .

CHAPTER VII

Review of Certain Conclusions resulting from the Bio¬ phoric Concept ........

Part II Heredity And Adaptation

On the Variability of the Bacteria and the Develop¬ ment of Races (1892) .

On Theories of Inheritance with Special Reference to the Inheritance of Acquired Conditions in Man (1901)

Adaptation and Inflammation (1905) .

The Myelins and Potential Fluid Crystalline Bodies of the Organism (1906) .

The Dominance of the Nucleus (1906)

PAGE

The Reductio ad Absurdum of Weismannism (1907) .

CONTENTS xv

CHAPTER VII

A Lecture on Life (1909) .

CHAPTER VIII

On Habits, Symptoms, and Disease (1911) .

CHAPTER IX

Parenteral Digestion and Immunity (1914)

Part III

On Growth and Overgrowth, and on the Relationship between Cell Differentiation and Proliferative Capacity (1900) .

On the Causation of Cancerous and other New Growths (1901) ..........

On the Classification of Tumours (1902) . . . .

Syncytioma (Deciduoma) Malignum : its Bearing upon the Essential Nature of Malignancy (1902)

Unipotentiality, Pluripotentiality, and Totipotentiality of Cells : a Note upon the Classification of Tumours (1907) .

PAGE xvi THE STUDY OF EVOLUTION

PAGE

On the Relationship between Tumours Proper (Blastomas)

and Hyperblastosis (1913) . . . . . . 340

APPENDIX I

The Experimental Production of Specific Variation in Typhoid Bacilli, by F. B. Bowman, M.B. (Tor.), Major, C.A.M.C . 351

Sir E. Ray Lankester rebukes Rudeness : a Correspond¬ ence in the Pages of the British Medical Journal . 354

Index .

ILLUSTRATIONS

PLATES

PLATE TO FACE PAGE

!• Fossil and recent blue -green Algae (after Walcott) . . 18

II. The Myelins : doubly refracting fatty globules from the adrenal

cortex and liver . . . . . . . .168

III. The Myelins : Myelin forms from soap ; Ductile Crystals

IV. The Myelins : Distortion of fluid crystals and aberrant forms

of myelin globules . . . . . . .186

V. Schema of the stages of fertilization of the ovum (after

Boveri) . 192

VI. Schema of tissue relationships . . . . . .312

VII. Diagram of a lepidic and a hylic tissue . . . .316

FIGURES IN THE TEXT

FIG. PAGE

1. Diagram of chemical constitution of an amino-acid nucleus of

2. Diagram of constitution of a protein ring . . . .76

3. Diagram of the affinities of a compound of two carbon atoms

(after Bayliss) . . . . . . . .77

4. Diagram of cell to show nuclear skein with chromomeres . . 78

5. Diagram of mode of growth and deduplication of the biophoric

6. Diagrammatic representation of the nature of enzyme action . 86

7. Diagram of simple dissociation of peptone molecule . . 87

8. Diagram of interaction of substratum and receptor through inter¬

mediation of enzyme . . . . . . .87 xvn xviii THE STUDY OP EVOLUTION

PIG. PAGE

9. Diagram of alteration in constitution of biophoric molecule . 89

10. Graphic formula of the Pyrimidine ring . . . .89

11. Diagram of production of multiple side-chain elements . . 90

12. Diagram of interchange of allelomorphic side-chains between

biophores of paternal and maternal origin . . .94

13. The different forms of chromosomes in the human spermato¬

cyte (after Moore and Arnold) . . . . .192

14. Cells of the salivary gland to show production and discharge

of “ plasmosomes ” (after Maximow) . . . .199

15. Aberrant mitoses (after v. Hansemann and Pianese) . . 201

16. Diagram of constitution of protein ling .... 207

17. Diagram of relationship between nuclear biophores and cyto¬

plasmic proteins . . . . . . . .208

18. Chromosomes, chromomeres and “ ids ” . . . . .214

19. Diagrammatic representation of constitution of protein or

peptone nucleus . . . . . . . .222

20. Diagram of growth of biophoric molecule . . . .228