THOMAS HENRY HUXLEY
Leaders in Science
THOMAS HENRY HUXLEY
A SKETCH OF HIS LIFE AND WORK
BY
P. CHALMERS MITCHELL, M.A. (Oxon.)
G.P. PUTNAM'S SONS
| NEW YORK 27 WEST TWENTY THIRD STREET | LONDON 24 BEDFORD STREET STRAND |
| The Knickerbocker Press 1900 | |
Copyright 1900
BY
G.P. PUTNAM'S SONS
The Knickerbocker Press, New York
[PREFACE]
This volume is in no sense an intimate or authorised biography of Huxley. It is simply an outline of the external features of his life and an account of his contributions to biology, to educational and social problems, and to philosophy and metaphysics. In preparing it, I have been indebted to his own Autobiography, to the obituary notice written by Sir Michael Foster for the Royal Society of London, to a sketch of him by Professor Howes, his successor at the Royal College of Science, and to his published works. The latter consist of many well-known separate volumes which are familiar to all zoölogists, and of a vast number of memoirs and essays scattered in various scientific and general publications. The general Essays were collected into nine volumes, revised by himself in the later years of his life, and published by Messrs. Macmillan. The Scientific Memoirs, thanks to the generous enterprise of the same publishing firm, with which he was so long associated, and to the pious labours of Sir Michael Foster and Professor Ray Lankester, are in process of reissue in the form of four volumes, two of which have now appeared. These will contain all his important contributions to science, with the exception of a large separate treatise on the Oceanic Hydrozoa published by the Ray Society in 1859. There is also announced a formal Biography, prepared by his son, so that future admirers or students of Huxley's work will be in an exceptionally favourable position.
London, 1900. P. CHALMERS MITCHELL.
Leaders in Science
[CONTENTS]
PAGE
[1]FROM SCHOOL TO LIFE-WORK
Birth—Parentage—School-days—Choice of Medical Profession—Charing Cross Hospital—End of Medical Studies—Admission to Naval Medical Service.
[13]THE VOYAGE OF THE RATTLESNAKE
The Objects of the Voyage—The Route—The Naturalist and the Surgeon—Collecting and Dredging—Stay in Sydney—Adventures with the Natives—Comparison with Darwin's Voyage on the Beagle.
[30]FLOATING CREATURES OF THE SEA
The Nature of Floating Life—Memoir on Medusæ Accepted by the Royal Society—Old and New Ideas of the Animal Kingdom—What Huxley Discovered in Medusæ—His Comparison of them with Vertebrate Embryos
[46]EARLY DAYS IN LONDON
Scientific Work as Unattached Ship-Surgeon—Introduction to London Scientific Society—Translating, Receiving, and Lecturing—Ascidians—Molluscs and the Archetype—Criticism of Pre-Darwinian Evolution—Appointment to Geological Survey.
[67]CREATURES OF THE PAST
Beginning Palæontological Work—Fossil Amphibia and Reptilia—Ancestry of Birds—Ancestry of the Horse—Imperfect European Series Completed by Marsh's American Fossils—Meaning of Geological Contemporaneity—Uniformitarianism and Catastrophism Compared with Evolution in Geology—Age of the Earth—Intermediate and Linear Types.
[89]HUXLEY AND DARWIN
Early Ideas on Evolution—Erasmus Darwin—Lamarck—Herbert Spencer—Difference between Evolution and Natural Selection—Huxley's Preparation for Evolution—The Novelty of Natural Selection—The Advantage of Natural Selection as a Working Hypothesis—Huxley's Unchanged Position with regard to Evolution and Natural Selection from 1860 to 1894.
[110]THE BATTLE FOR EVOLUTION
Huxley's Prevision of the Battle—The Causes of the Battle—The Times Review—Sir Richard Owen attacks Darwinism in the Edinburgh Review—Bishop Wilberforce attacks in the Quarterly Review—Huxley's Scathing Replies—The British Association Debates at Oxford—Huxley and Wilberforce—Résumé of Huxley's Exact Position with Regard to Evolution and to Natural Selection.
[128]VERTEBRATE ANATOMY
The Theory of the Vertebrate Skull—Goethe, Oken, Cuvier, and Owen—Huxley Defends Goethe—His own Contributions to the Theory—The Classification of Birds—Huxley Treats them as "Extinct Animals"—Geographical Distribution—Sclater's Regions—Huxley's Suggestions.
[144]MAN AND THE APES
Objections to Zoölogical Discussion of Man's Place—Owen's Prudence—Huxley's Determination to Speak out—Account of his Treatment of Man's Place in Nature—Additions Made by More Recent Work.
[167]SCIENCE AS A BRANCH OF EDUCATION
Science-Teaching Fifty Years Ago—Huxley's Insistence on Reform—Science Primers—Physiography—Elementary Physiology—The Crayfish—Manuals of Anatomy—Modern Microscopical Methods—Practical Work in Biological Teaching—Invention of the Type System—Science in Medical Education—Science and Culture.
[188]GENERAL PROBLEMS OF EDUCATION
Establishment of Compulsory Education in England—The Religious Controversy—Huxley Advocates the Bible without Theology—His Compromise on the "Cowper-Temple" Clause—Influence of the New Criticism—Science and Art Instruction—Training of Teachers—University Education—The Baltimore Address—Technical Education—So-called "Applied Science"—National Systems of Education as "Capacity-Catchers."
[204]CITIZEN, ORATOR, AND ESSAYIST
Huxley's Activity in Public Affairs—Official in Scientific Societies—Royal Commissions—Vivisection—Characteristics of his Public Speaking—His Method of Exposition—His Essays—Vocabulary—Phrase-Making—His Style Essentially One of Ideas.
[218]THE OPPONENT OF MATERIALISM
Science and Metaphysics—Berkeley, Hume, and Hobbes—Existence of Matter and Mind—Descartes's Contribution—Materialism and Idealism—Criticism of Materialism—Berkeley's Idealism—Criticism of Idealism—Empirical Idealism—Materialism as opposed to Supernaturalism—Mind and Brain—Origin of Life—Teleology, Chance, and the Argument from Design.
[232]FREEDOM OF THOUGHT
Authority and Knowledge in Science—The Duty of Doubt—Authority and Individual Judgment in Religion—The Protestant Position—Sir Charles Lyell and the Deluge—Infallibility—The Church and Science—Morality and Dogma—Civil and Religious Liberty—Agnosticism and Clericalism—Meaning of Agnosticism—Knowledge and Evidence—The Method of Agnosticism.
[245]THE BIBLE AND MIRACLES
Why Huxley Came to Write about the Bible—A Magna Charta of the Poor—The Theological Use of the Bible—The Doctrine of Biblical Infallibility—The Bible and Science—The Three Hypotheses of the Earth's History—Changes in the Past Proved—The Creation Hypothesis—Gladstone on Genesis—Genesis not a Record of Fact—The Hypothesis of Evolution—The New Testament—Theory of Inspiration—Reliance on the Miraculous—The Continuity of Nature no a priori Argument against Miracles—-Possibilities and Impossibilities—Miracles a Question of Evidence—Praise of the Bible.
[261]ETHICS OF THE COSMOS
Conduct and Metaphysics—Conventional and Critical Minds—Good and Evil—Huxley's Last Appearance at Oxford—The Ethical Process and the Cosmic Process—Man's Intervention—The Cosmic Process Evil—Ancient Reconciliations—Modern Acceptance of the Difficulties—Criticism of Huxley's Pessimism—Man and his Ethical Aspirations Part of the Cosmos.
[275]CLOSING DAYS AND SUMMARY
Huxley's Life in London—Decennial Periods— Ill-health—Retirement to Eastbourne—Death—Personal Appearance—Methods of Work—Personal Characteristics—An Inspirer of Others—His Influence in Science—A Naturalist by Vocation—His Aspirations.
ILLUSTRATIONS
PAGE
[Frontispiece] THOMAS HENRY HUXLEY
From a photograph by London Stereoscopic Company
[64]THOMAS HENRY HUXLEY, 1857
Reproduced by permission from "Natural Science," vol. vii., No. 42
[98]SIR JOSEPH DALTON HOOKER
From a photograph by Elliott and Fry, London
[146]CHARLES DARWIN
From the painting by Hon. John Collier in the National Portrait Gallery
[236]SIR CHARLES LYELL
From a photograph by London Stereoscopic Company
[276]CARICATURE OF HUXLEY DRAWN BY HIMSELF
Reproduced by permission from "Natural Science," vol. vii., No. 46.
LIST OF HUXLEY'S WRITINGS
This list is offered, not as a bibliography in the technical sense, but as an indication of the sources in which the vast majority of Huxley's scientific and general work may be consulted most conveniently.
The Scientific Memoirs of Thomas Henry Huxley. Edited by Professor Sir Michael Foster and Professor E. Ray Lankester; in four volumes. London, Macmillan & Co.; New York, D. Appleton.
This magnificent collection is intended to contain all Huxley's original scientific papers, brought together from the multitude of scientific periodicals in which they appeared, with reproductions of the original illustrations. The only exception is the monograph on Oceanic Hydrozoa. The first volume appeared in 1898; the second in 1899, and the others are to follow quickly.
Collected Essays by T.H. Huxley; nine volumes of the Eversley Series. Macmillan & Co. London, 1893-95.
This set, edited by Huxley himself, contains the more important of his more general contributions to science and his literary, philosophical, and political and critical essays. Each volume has a preface specially written, and the first volume contains his autobiography.
The Oceanic Hydrozoa; a description of the Calycophoridæ and Physophoridæ observed during the Voyage of H.M.S. Rattlesnake in the years 1846-50, with a general introduction. Ray Society. London, 1859.
Evidence as to Man's Place in Nature. Williams & Norgate. London, 1863.
On our Knowledge of the Causes of Organic Phenomena; being Six Lectures to Working Men. Hardwicke. London, 1863.
Lectures on the Elements of Comparative Anatomy. On the Classification of Animals and the Vertebrate Skull. Churchill & Sons. London, 1864.
An Elementary Atlas of Comparative Osteology. In twelve plates. Williams & Norgate. London, 1864.
Lessons in Elementary Physiology. Macmillan & Co. London, 1866.
An Introduction to the Classification of Animals. Churchill. London, 1869.
A Manual of the Anatomy of Vertebrated Animals. Churchill. London, 1871.
A Course of Practical Instruction in Elementary Biology, assisted by H.N. Martin. Macmillan. London, 1875.
A Manual of the Anatomy of Invertebrated Animals. Churchill. London, 1877.
Lay Sermons, Essays, and Reviews. Macmillan. London, 1877.
American Addresses, with a Lecture on the Study of Biology. Macmillan. London, 1877.
Physiography, an Introduction to the Study of Zoölogy. International Scientific Series. Kegan Paul. London, 1880.
Introductory Primer. Science Primers. Macmillan. London, 1880.
The Life and Letters of Charles Darwin. Edited by his son, Francis Darwin. Volume II., with Chapter V. by Professor Huxley on the Reception of the Origin of Species. John Murray. London, 1887.
Life of Richard Owen. By his grandson. With an Essay on Owen's Position in Anatomical Science, by T.H. Huxley. John Murray. London, 1894.
THOMAS HENRY HUXLEY
[CHAPTER I]
FROM SCHOOL TO LIFE-WORK
Birth—Parentage—School-days—Choice of Medical Profession—Charing Cross Hospital—End of Medical Studies—Admission to Naval Medical Service.
Some men are born to greatness: even before their arrival in the world their future is marked out for them. All the advantages that wealth and the experience of friends can bring attend their growth to manhood, and their success almost loses its interest because of the ease with which it is attained. Few of the leaders of science were in such a position: many of them, such as Priestley, Davy, Faraday, John Hunter, and Linnæus were of humble parentage, and received the poorest education: most of them, like Huxley himself, have come from parents who were able to do little more for their children than set them out into life along the ordinary educational avenues. In Huxley's boyhood at least a comfortable income was necessary for this: in every civilised country nowadays, state endowments, or private endowments, are ready to help every capable boy, as far as Huxley was helped, and in his progress from boyhood to supreme distinction, there is nothing that cannot be emulated by every boy at school to-day. The minds of human beings when they are born into the world are as naked as their bodies; it matters not if parents, grandparents, and remoter ancestors were unlettered or had the wisdom of all the ages, the new mind has to build up its own wisdom from the beginning. We cannot even say with certainty that children inherit mental aptitudes and capacities from their parents; for as tall sons may come from short parents or beautiful daughters from ugly parents, so we may find in the capacities of the parents no traces of the future greatness of their children. None the less it is interesting to learn what we can about the parents of great men; and Huxley tells us that he thinks himself to have inherited many characters of his body and mind from his mother.
Thomas Henry Huxley was born on the 4th of May, 1825, at Ealing, then a little country village, now united to London as a great suburb. He was the seventh child of George Huxley, who was second master at the school of Dr. Nicholson at Ealing. In these days private schools of varying character were very numerous in England, and this establishment seems to have been of high-class character, for Cardinal Newman and many other distinguished men received part of their education there. His mother, whose maiden name was Rachel Withers, was, he tells us himself:[A]
"A slender brunette of an emotional and energetic temperament, and possessed of the most piercing black eyes I ever saw in a woman's head. With no more education than other women of the middle classes in her day, she had an excellent mental capacity. Her most distinguishing characteristic, however, was rapidity of thought. If one ventured to suggest she had not taken much time to arrive at any conclusion, she would say, 'I cannot help it. Things flash across me.' That peculiarity has been passed on to me in full strength: it has often stood me in good stead: it has sometimes played me sad tricks, and it has always been a danger. But, after all, if my time were to come over again there is nothing I would less willingly part with than my inheritance of 'mother wit.'"
From his father he thinks that he inherited little except an inborn capacity for drawing, "a hot temper, and that amount of tenacity of purpose which unfriendly observers sometimes call obstinacy." As it happened, this natural gift for drawing proved of the greatest service to him throughout his career. It is imperative that every investigator of the anatomy of plants and animals should be able to sketch his observations, and there is no greater aid to seeing things as they are than the continuous attempt to reproduce them by pencil or brush.
Huxley was christened Thomas Henry, and he was unaware why these names were chosen, but he humorously records the curious chance that his parents should have chosen for him the "name of that particular apostle with whom he had always felt most sympathy."
Of his childhood little is recorded. He remembers being vain of his curls, and his mother's expressed regret that he soon lost the beauty of early childhood. He attended for some time the school at Ealing with which his father was associated, but he has little to say for the training he received there. He writes:
"My regular school training was of the briefest, perhaps fortunately: for, though my way of life has made me acquainted with all sorts and conditions of men, from the highest to the lowest, I deliberately affirm that the society I fell into at school was the worst I have ever known. We boys were average lads with much the same inherent capacity for good and evil as any others; but the people who were set over us cared about as much for our intellectual and moral welfare as if they were baby-farmers. We were left to the operation of the struggle for existence among ourselves, and bullying was the least of the ill practices current among us. Almost the only cheerful reminiscence in connection with the place which arises in my mind is that of a battle which I had with one of my class-mates, who had bullied me until I could stand it no longer. I was a very slight lad, but there was a wild-cat element in me which, when roused, made up for my lack of weight, and I licked my adversary effectually. However, one of my first experiences of the extremely rough and ready nature of justice, as exhibited by the course of things in general, arose out of the fact that I—the victor—had a black eye, while he—the vanquished—had none, so that I got into disgrace and he did not. One of the greatest shocks I ever received in my life was to be told, a dozen years afterwards by the groom who brought me my horse in a stable-yard in Sydney, that he was my quondam antagonist. He had a long story of family misfortune to account for his position—but at that time it was necessary to deal very cautiously with mysterious strangers in New South Wales, and on enquiry I found that the unfortunate young man had not only been 'sent out,' but had undergone more than one colonial conviction."
Huxley was soon removed from school and continued his own education for several years, by reading of the most desultory sort. His special inclinations were towards mechanical problems, and had he been able to follow his own wishes there is little doubt but that he would have entered on the profession of an engineer. It is probable that there was a great deal more in his wishes than the familiar inclination of a clever boy to engineering. All through the pursuit of anatomy, which was the chief business of his life, it was the structure of animals, the different modifications of great ground-plans which they presented, that interested him. But the opportunity for engineering did not present itself, and at an exceedingly early age he began to study medicine. Two brothers-in-law were doctors, and this accidental fact probably determined his choice. In these days the study of medicine did not begin as now with a general and scientific education, but the young medical student was apprenticed to a doctor engaged in practice. He was supposed to learn the compounding of drugs in the dispensary attached to the doctor's consulting-room; to be taught the dressing of wounds and the superficial details of the medical craft while he pursued his studies in anatomy under the direction of the doctor. Huxley's master was his brother-in-law, Dr. Salt, a London practitioner, and he began his work when only twelve or thirteen years of age. In this system everything depended upon the superior; under the careful guidance of a conscientious and able man it was possible for an apt pupil to learn a great deal of science and to become an expert in the treatment of disease. Huxley, however, had only a short experience of this kind of training. He was taken by some senior student friends to a post-mortem examination, and although then, as all through his life, he was most sensitive to the disagreeable side of anatomical pursuits, on this occasion he gratified his curiosity too ardently. He did not cut himself, but in some way poisonous matter from the body affected him, and he fell into so bad a state of health that he had to be sent into the country to recruit. He lived for some time at a farmhouse in Warwickshire with friends of his father and slowly recovered health. From that time, however, all through his life, he suffered periodically from prostrating dyspepsia. After some months devoted to promiscuous reading he resumed his work under his brother-in-law in London. He confesses that he was far from a model student.
"I worked extremely hard when it pleased me, and when it did not,—which was a frequent case,—I was extremely idle (unless making caricatures of one's pastors and masters is to be called a branch of industry), or else wasted my energies in wrong directions. I read everything I could lay hands upon, including novels, and took up all sorts of pursuits to drop them again quite speedily."
It is almost certain, however, that Huxley underestimated the value of this time. He stored his mind with both literature and science, and laid the foundation of the extremely varied intellectual interests which afterwards proved to him of so much value. It is certain, also, that during this time he acquired a fair knowledge of French and German. It would be difficult to exaggerate the value to him of this addition to his weapons for attacking knowledge. To do the best work in any scientific pursuit it is necessary to freshen one's own mind by contact with the ideas and results of other workers. As these workers are scattered over different countries it is necessary to transcend the confusion of Babel and read what they write in their own tongues. When Huxley was young, the great reputation of Cuvier overshadowed English anatomy, and English anatomists did little more than seek in nature what Cuvier had taught them to find. In Germany other men and other ideas were to be found. Johannes Mueller and Von Baer were attacking the problems of nature in a spirit that was entirely different, and Huxley, by combining what he was taught in England with what he learned from German methods, came to his own investigations with a wider mind. But his conquest of French and German brought with it advantages in addition to these technical gains. There is no reason to believe that he troubled himself with grammatical details and with the study of these languages as subjects in themselves. He acquired them simply to discover the new ideas concealed in them, and he by no means confined himself to the reading of foreign books on the subjects of his own studies. He read French and German poetry, literature, and philosophy, and so came to have a knowledge of the ideas of those outside his own race on all the great problems that interest mankind. A good deal has been written as to the narrowing tendency of scientific pursuits, but with Huxley, as with all the scientific men the present writer has known, the mechanical necessity of learning to read other languages has brought with it that wide intellectual sympathy which is the beginning of all culture and which is not infrequently missed by those who have devoted themselves to many grammars and a single literature. The old proverb, "Whatever is worth doing is worth doing well," has only value when "well" is properly interpreted. Although the science of language is as great as any science, it is not the science of language, but the practical interpretation of it, that is of value to most people, and there is much to be said for the method of anatomists like Huxley, who passed lightly over grammatical minutiæ and went straight with a dictionary to the reading of each new tongue.
After a short period of apprenticeship, or sometimes during the course of it, the young medical students "walked" a hospital. This consisted in attending the demonstrations of the physicians and surgeons in the wards of the hospital and in pursuing anatomical, chemical, and physiological study in the medical school attached to the hospital. A large fee was charged for the complete course, but at many of the hospitals there were entrance scholarships which relieved those who gained them of all cost. In 1842 Huxley and his elder brother, James, applied for such free scholarships at Charing Cross Hospital. There is no record in the books of the hospital as to what persons supported the application. The entry in the minutes for September 6, 1842, states that
"Applications from the following gentlemen (including the two sons of Mr. George Huxley, late senior assistant master in Ealing School), were laid before the meeting, and their testimonials being approved of, it was decided that those gentlemen should be admitted as free scholars, if their classical attainments should be found upon examination to be satisfactory."
It appears that the two Huxleys were able to satisfy the probably unexacting demands of the classical examiners, for they began their hospital work in October of the same year.
Those who know the magnificent laboratories and lecture-rooms which have grown up in connection with the larger London hospitals must have difficulty in realising the humble arrangements for teaching students in the early forties. What endowments there were—and Charing Cross was never a richly endowed hospital—were devoted entirely to the hospital as opposed to the teaching school. There were no separate buildings for anatomy, physiology, and so forth. At Charing Cross the dissecting-room was in a cellar under the hospital, and subjects like chemistry, botany, physiology, and so forth were crowded into inconvenient side rooms. The teachers were not specialists, devoting their whole attention to particular branches of science, but were doctors engaged in practice, who, in addition to their private duties and their work at the hospital, each undertook to lecture upon a special scientific subject. Huxley came specially under the influence of Mr. Wharton Jones, who had begun to teach physiology at the hospital a year before. Mr. Jones throughout his life was engaged in professional work, his specialty being ophthalmic surgery, but he was a devoted student of anatomy and physiology, and made several classical contributions to scientific knowledge, his best-known discoveries relating to blood corpuscles and to the nature of the mammalian egg-cell. But perhaps his greatest claim to fame is that it was he who first imbued Huxley with a love for anatomical science and with a knowledge of the methods of investigation. At the end of his first session, in 1843, Huxley received the first prize in the senior physiology class, while his brother got a "good conduct" prize. Of Wharton Jones Huxley writes:
"The extent and precision of his knowledge impressed me greatly, and the severe exactness of his method of lecturing was quite to my taste. I do not know that I have ever felt so much respect for anybody as a teacher before or since. I worked hard to obtain his approbation, and he was extremely kind and helpful to the youngster who, I am afraid, took up more of his time than he had any right to do. It was he who suggested the publication of my first scientific paper—a very little one—in the Medical Gazette of 1845, and most kindly corrected the literary faults which abounded in it short as it was. For at that time, and for many years afterwards, I detested the trouble of writing and would take no pains over it."
This little paper, although Huxley deprecates it, was remarkable as the work of so young an investigator. In it he demonstrated the existence of a hitherto unrecognised layer in the inner root-sheath of hairs, a layer that has been known since as Huxley's layer.
There is no record in the minutes of the hospital school that Huxley gained any other school prizes. His name reappears only in formal applications at the beginning of each session for the renewal of his free scholarship. In this respect he is in marked contrast to his fellow-student, afterwards Sir Joseph Fayrer, who appears to have taken almost every prize open to him. On the other hand, his attainments in anatomy and physiology brought him distinction in a wider field than the hospital school, for he obtained, in the "honours" division of the first examination for the degree of Bachelor of Medicine at the University of London, the second place with a medal. And it is certain that he was far from neglecting his strictly professional work, although, no doubt, he devoted much time to reading and research in pure science, for in the winter of 1845-46, having completed his course at the hospital, he was prepared to offer himself at the examination for the membership of the Royal College of Surgeons; but, being as yet under twenty-one years of age, could not be admitted as a candidate.
It was now time for Huxley definitely to enter on his profession. He would have preferred to continue his investigations in London and to wait for the chance of a teaching post in physiology, but it was necessary to earn a living. One of those whom he consulted was his fellow-student, Joseph Fayrer, who, hailing from Bermuda, knew something of those who go down to the sea in ships. He advised Huxley to write to Sir William Burnett, at that time Director-General for the medical service of the navy, for an appointment.
"I thought this rather a strong thing to do," says Huxley in his autobiography, "as Sir William was personally unknown to me; but my cheery friend would not listen to my scruples, so I went to my lodgings and wrote the best letter I could devise. A few days afterwards I received the usual official circular of acknowledgement, but at the bottom was written an instruction to call at Somerset House on such a day. I thought that looked like business, so, at the appointed time I called and sent in my card, while I waited in Sir William's ante-room. He was a tall, shrewd-looking old gentleman, with a broad Scotch accent—and I think I see him now as he entered with my card in his hand. The first thing he did was to return it with the frugal reminder that I should probably find it useful on some other occasion. The second was to ask whether I was an Irishman. I suppose the air of modesty about my appeal must have struck him. I satisfied the Director-General that I was English to the backbone, and he made some enquiries as to my student career, finally desiring me to hold myself ready for examination. Having passed this, I was in Her Majesty's service, and entered on the books of Nelson's old ship, the Victory, for duty at Haslar Hospital, about a couple of months after I made my application."
About the same time he passed the examination of the Royal College of Surgeons and so became a fully qualified medical man. Haslar Hospital was the chief naval hospital to which invalided sailors were sent. There was a considerable staff of young surgeons, as navy surgeons were usually sent for a term to work in the hospital before being gazetted to a ship in commission. In connection with the hospital, there was a museum of natural history containing a collection of considerable importance slowly gathered from the gifts of sailors and officers. The museum curator was an enthusiastic naturalist, and Huxley must have had the opportunity of extending his knowledge of at least the external characters of many forms of life hitherto unknown to him. A few years later, the curator of the museum, with the help of two of Huxley's successors, published a Manual of Natural History for the Use of Travellers, and it is certain that Huxley at least did not lose at Haslar any of the enthusiasm for zoölogy with which he had been inspired at the Charing Cross Hospital. The chief of the hospital was Sir John Richardson, an excellent naturalist, and well known as an arctic explorer. He seems to have recognised the peculiar ability of his young assistant, and although he was a silent, reserved man, who seldom encouraged his assistants by talking to them, he made several attempts to obtain a suitable post for Huxley. Such a post was that of surgeon to H.M.S. Rattlesnake, then about to start under the command of Captain Owen Stanley for surveying work in the Torres Straits. Captain Stanley had expressed a wish for a surgeon who knew something of science, and, on the recommendation of Sir John Richardson, obtained the post for Huxley. There was, however, to be a special naturalist attached to the expedition, but Huxley had the opportunity he wanted. After a brief stay of seven months at the Haslar Hospital he left it for his ship, and thus definitely entered on his work in the world.
FOOTNOTES:
[A] This and many other details in this chapter are taken from an autobiographical sketch in the first volume of Huxley's collected essays published by Macmillan, London, 1894.
[CHAPTER II]
THE VOYAGE OF THE "RATTLESNAKE"
The Objects of the Voyage—The Route—The Naturalist and the Surgeon—Collecting and Dredging—Stay in Sydney—Adventures with the Natives—Comparison with Darwin's Voyage on the Beagle.
Her Majesty's ship the Rattlesnake, one of the old class of 28-gun ships, sailed from Plymouth for the Torres Straits and the Australian seas on December 12, 1846. Her commander was Captain Owen Stanley, a young but distinguished officer, the son of the Bishop of Norwich and a brother of Dean Stanley, who afterwards played so great a part in the social and religious history of England. She carried a complement of 180 officers and men, and was attended by the Bramble and the Castlereagh, two small vessels of light draught, whose purpose was to precede her in shallow waters. The young colonies of Australia were developing commerce with the mother country, and the business of the Rattlesnake was to survey the waters round about the Torres Straits, that the passage towards India on the homeward trip might be made safer. Incidentally the vessel was to land a treasure of £50,000 at the Cape of Good Hope, and another of £15,000 at the Mauritius. The Admiralty Commissioners left full powers to Captain Stanley to carry out the details of his mission according to his own judgment, but he was solemnly warned upon two points. Many very unfortunate casualties had occurred when sailors came in contact with the little-known savages of the southern seas, and the Admiralty instructed him as follows:
"In stretching off from the Barrier Reefs to the eastward, in order to explore the safety of the sea intervening between them and Louisiade and New Guinea, you will have occasion to approach these shores, in which case you must constantly be on your guard against the treacherous disposition of their inhabitants. All barter for refreshments must be conducted under the eye of an officer, and every pains be taken to avoid giving any just cause of offence to their prejudices, especially with respect to their women."
The second warning concerned grave international matters. European politics were in the unsettled condition which, after the illusive international courtesies of the Great Exhibition of 1851, ended in the Crimean War, and it was feared that in the event of hostilities breaking out, the zeal of the officers for their country might tempt them to transcend their peaceful occupation. The instructions with regard to this ran as follows:
"In the event of this country being involved in hostilities during your absence, you will take care never to be surprised; but you are to refrain from any act of aggression towards the vessels or settlements of any nation with which we may be at war, as expeditions employed on behalf of discovery and science have always been considered by all civilised communities as acting under a general safeguard."
The great scientific expeditions sent out in recent times by the governments of Britain, Germany, and the United States, were fitted with every convenience for the staff of naturalists, and the luxuries and comforts of civilisation attended them round the world. The late Professor Mosely, for instance, who was a naturalist on the English Challenger expedition, told the present writer of a pleasant way in which a peculiarity of the deep sea was made to pay toll to the comfort of those on board ship. The great ocean depths all over the world, under the burning skies of the tropics, or below the arctic ice-fields, are extremely cold, the water at the bottom always being only a few degrees above freezing point. When the dredge brought up a sample of the abysmal mud at a convenient time, it was used to ice the wine for the officers' mess. There was, however, no cooled champagne for Huxley.
"Life on board Her Majesty's ships in those days," he writes, "was a very different affair from what it is now, and ours was exceptionally rough, as we were often many months without receiving letters or seeing any civilised people but ourselves. In exchange, we had the interest of being about the latest voyagers, I suppose, to whom it could be possible to meet with people who knew nothing of fire-arms—as we did on the south coast of New Guinea—and of making acquaintances with a variety of interesting savage and semi-civilised people. But apart from experience of this kind, and the opportunities offered for scientific work, to me personally the cruise was extremely valuable. It was good for me to live under sharp discipline; to be down on the realities of existence by living on bare necessities; to find out how extremely well worth living life seemed to be when one woke up from a night's rest on a soft plank with the sky for canopy, and cocoa and weevilly biscuit the sole prospect for breakfast; and more especially to learn to work for the sake of what I got for myself out of it, even if it all went to the bottom and I myself along with it. My brother officers were as good fellows as sailors ought to be, and generally are, but naturally they neither knew nor cared anything about my pursuits, nor understood why I should be so zealous in pursuit of the objects which my friends the middies christened 'Buffons,' after the title conspicuous on a volume of the Suites à Buffon which stood on my shelf in the chart-room."
Huxley was only the surgeon on board the Rattlesnake, and his pursuit of natural history was his own affair. There was a special naturalist appointed to the expedition, no doubt chosen because four years earlier, as assistant to Professor Jukes, he had been attached as naturalist to the expedition of the Fly in the same waters. His name was John MacGillivray, and he was the son of an exceedingly able naturalist whose reputation has been overshadowed by the greater names of the middle century. William MacGillivray, the father, sometime professor at the University of Aberdeen, was one of those driven by an almost instinctive desire to the study of nature. In his youth, when he was a poor lad, desiring to see as much as possible of his native land, and above all to visit the great museums and libraries of the south, he walked from Aberdeen to London with no luggage but a copy of Smith's Flora Britannica. He was an ardent botanist, a collector of insects and molluscs, and one of the pioneers in the anatomy of birds. There are many curious allusions in his writings which seem to shew that he too was beginning to doubt the fixity of species, and to guess at the struggle for existence and survival of the fittest which the great Darwin was the first to make a part of the knowledge of the world. It must be confessed that his son John, the companion of Huxley, had little of his father's ability. He was three years older than Huxley, and broke off his medical course at the University of Edinburgh to sail in the Fly. After the return of the Rattlesnake, he was appointed in 1852 as naturalist to H.M.S. Herald, then starting under Captain Denham for surveying work round the shores of South America. He left that ship at Sydney, and after many years' wandering about the southern seas, accounts of which he communicated from time to time to Sydney newspapers, he died in 1867. He was a zealous collector of plants and animals, but apparently cared little for the study of his captures, either in life, in relation to their surroundings, like Darwin, or for the structure of their bodies, like Huxley. The somewhat unpleasing nature of his regard for animals appears in the following story which he himself tells:
"While at dinner off Darnley Island near the Torres Straits, news was brought that Dzum was under the stern in a canoe, shouting out loudly for Dzoka (MacGillivray's native name), and, on going up I found that he had brought off the barit, which after a deal of trouble I struck a bargain for and obtained. It was a very fine specimen of Cuscus Maculatus, quite tame and kept in a large cage of split bamboo. Dzum seemed very unwilling to part with the animal, and repeatedly enjoined me to take great care of it and feed it well, which to please him I promised to do, although I valued it merely for its skin, and was resolved to kill it for that purpose at my first convenience."
On the other hand, MacGillivray paid great attention to native languages, and collected vocabularies of some value. To him was entrusted the task of writing an account of the voyage, and it is from his rather dull pages, brightened by illustrations from Huxley's sketches, that the incidents of the voyage are taken. The references to Huxley in the narrative are slight, and seem to shew that no great intimacy existed between the two young men, the one a naturalist by profession, the other as yet a surgeon, but more devoted to natural history than the naturalist. Such references as occur relate to Huxley's constant occupations on shore, sketching natives and their dwellings, and his apparatus on board for trawling, dredging, and dissecting.
The voyage out was uneventful. The ship touched at Madeira and at Rio de Janeiro, and then crossed the South Atlantic to Simon's Town at the Cape of Good Hope, where the first quantity of treasure was to be landed. There they found the colony distressed by the long continuance of the Kaffir war. Prices for everything were extortionate, and the colonists had no mind for any affairs than their own, so after a short stay the voyagers were glad to set out for the Mauritius. That island, although in the possession of Britain, still retained a strong impress of its French occupation, and the travellers were interested by the mixture of population inhabiting it.[B]
"Passing through the closely packed lines of shipping, and landing as a stranger at Port Louis, perhaps the first thing to engage attention is the strange mixture of nations,—representatives, he might at first be inclined to imagine, of half the countries of the earth. He stares at a coolie from Madras with a breech-cloth and a soldier's jacket, or a stately bearded Moor striking a bargain with a Parsee merchant. A Chinaman with two bundles slung on a bamboo hurries past, jostling a group of young Creole exquisites smoking their cheroots at a corner, and talking of last night's Norma, or the programme of the evening's performance at the Hippodrome in the Champ de Mars. His eye next catches a couple of sailors reeling out of a grogshop, to the amusement of a group of laughing negresses, in white muslin dresses of the latest Parisian fashion, contrasting strongly with a modestly attired Cingalese woman, and an Indian ayah with her young charge. Amidst all this, the French language prevails; and everything more or less pertains of the French character, and an Englishman can scarcely believe that he is in one of the colonies of his own country."
From Mauritius they proceeded to the English-looking colony of Tasmania, and after a few days set out for Sydney, arriving there on July 16th. The surveying officers had tedious work to do there, and Huxley stayed in Sydney for three months. Then, and in the course of three other prolonged stays in that town during the expedition, Huxley entered into the society of the town and became a general favourite. He is still remembered there, and the accompanying illustration[C] is a copy of an original sketch of himself, now in the possession of an Australian lady. He drew it on the fly-leaf of a volume of Lytton's poems and presented it on her birthday to the little daughter of a friend. At Sydney, too, he met and gained the love of the lady, then Miss Henrietta A. Heathorn, who afterwards became his wife.
On October 11th the Rattlesnake sailed northwards to begin the real work of the expedition. The great island of New Guinea, lying to the north of Australia, is separated from it only by the comparatively narrow Torres Straits. Through these lies the natural route for the commerce between Australia and the Northern Hemisphere. The eastward prolongation of New Guinea, and the coast of Queensland, enclose between them a great tropical sea which gradually converges to the Straits. The waters are very tempestuous, and the navigation is made more dangerous by the thousands of coral islands and coral reefs that stud the ocean. Following the shoreline of Queensland, at a distance of from ten to one hundred and fifty miles, and stretching for twelve hundred and fifty miles, is the Great Barrier Reef of Australia, one of the wonders of the world. The shelving floor of the ocean rises nearly to the surface along this line, and vast colonies of coral building creatures have formed their reefs up to the water's edge along the ridge. The turbulent waves scouring over this living mass have carved and moulded it into millions of fantastic islands, sometimes heaping detached masses of dead debris high above the surface of the water. At low tide the most wonderful fields of the animal flowers of the sea are exposed. Some of them form branching systems of hard skeletons like stony trees, the soft, brightly coloured animals dotted over the stems like buds. Others form solid masses; others, again, rounded skull like boulders, or elevations like toadstools. The colours of the skeletons and the animals are vivid scarlets and purples and greens. Sea anemones, shell-fish, and starfish of the most vivid hues are as abundant as the corals. Brilliant fish dart through the blossoms of the marine gardens, and sea birds scream and wheel in the air. The whole region is a paradise for the naturalist. Along the seaward side of the reef the great ocean surges and thunders perpetually. Between it and the shore the quiet channel glows under the tropical skies. It was amid such scenes as these that the Rattlesnake moved for nearly four years in the slow work of taking soundings, fixing the exact position of channels through the outer reef by slow triangular measurements, and generally preparing for the safety of the commerce of all nations. The ship went first up to Port Curtis in Brisbane; then fetched back to Sydney. Its next trip was south to the strait between Tasmania and Australia, then back to Sydney; then again along the Barrier Reef right up to the Torres Straits. After work there, it returned again to Sydney, and then set out for the Louisiade Archipelago, which stretches through the coral sea south-eastward from New Guinea; then again to the Australian shores of the Torres Straits, and finally arrived in Sydney in March, 1850, where the Captain suddenly died, and the ship was ordered to return to England.
Throughout the voyage MacGillivray and Huxley busied themselves with collecting animals on sea and on shore. MacGillivray seems to have taken for his share of the spoil chiefly such animals as provided shells or skins or skeletons suitable for handing over to museums. Huxley occupied himself incessantly with dissecting tools and with the microscope, with results to be described in a later chapter. The better equipped expeditions of modern times were provided with elaborate appliances for bringing up samples of living creatures from all depths of the floor of the ocean, and with complicated towing nets for securing the floating creatures of the surface of the seas. The Rattlesnake naturalists had to content themselves with simple apparatus devised by themselves. At an early period of the voyage attempts were made to take deep soundings, but no bottom was reached at a depth of two thousand four hundred fathoms, and their later work was confined to surface animals or to inshore dredging in shallow waters. They began near Rio.
"None of the ship's boats could be spared, so I [MacGillivray] hired one pulled by four negro slaves who, although strong, active fellows, had great objections to straining their backs at the oar, when the dredge was down. No sieve having been supplied, we were obliged to sift the contents of the dredge through our hands—a tedious and superficial mode of examination. Two days after, Mr. Huxley and I set to work in Botafogo Bay, provided with a wire-gauze meat-cover and a curious machine for cleaning rice; these answered capitally as substitutes for sieves, and enabled us, by a thorough examination of the contents of the dredge, to detect some forty-five species of Mollusca and Radiata, some of which were new to science."
By "new to science" MacGillivray meant no more than that the particular genera and species had not been captured before. Huxley, by his anatomical work, showed many of the most familiar creatures in a light "new to science," by revealing their true structure and relationships.
"Among the acquisitions," MacGillivray goes on, "I may mention a new species of Amphioxus, a genus of small fishes exhibiting more anomalies than any other known to Ichthyologists, and the lowest organisation found in the class. It somewhat resembles the sand-eels of Britain in habits, like them moving with extraordinary rapidity through the sand. By dint of bribery and ridicule we had at length managed to get our boatmen to work tolerably well, and when we were alike well-roasted by the sun and repeatedly drenched, besides being tired out and hungry, they had become quite submissive, and exchanged their grumbling for merriment."
The towing net repeatedly produced a rich harvest. It was constructed by themselves, and consisted of a bag of the bunting used for flags, two feet deep, the mouth being sewn round a wooden hoop fourteen inches in diameter; three pieces of cord, a foot and a half long, were secured to the hoop at equal intervals and had their ends tied together. This net was towed behind the ship by a stout cord. The water passed through the meshes of the cloth and left behind in the pocket any small floating animals.
Excursions ashore to the little savage islands or to the mainland were a source of constant interest, and it cannot be doubted that the acquaintance Huxley thus gained with many of the very low savages of Australia and New Guinea prepared his mind for the revolutionary doctrine of descent which he embraced a few years later. At the present time, there are probably very few parts of earth where there are yet to be found savages unaltered by civilisation. Some of the low races with which Huxley came in contact are now extinct. All the survivors have come in contact with white races, and their habits and customs have been altered. Before long the total extinction of these lower races is to be expected, and there will then be left an enormous gap between the lower animals and the dominant, aggressive, yellow and white races which are spreading over the earth and making the lower races perish before them, as the smaller but more cunning European rat has exterminated the native brown rat of Australia. In their various excursions upon the Australian mainland they had no trouble of any kind with the natives. These were at first suspicious of the doings of the white men, and their total ignorance of the use of firearms tempted them to rashness; but a few friendly gifts, and the exercise of tact in negotiating exchanges with them, made all the encounters pass off pleasantly. On the other hand, in the Louisiade Archipelago where the savages were of a higher type, difficulties constantly occurred. On one occasion, in a bay on the south side of Joannet Island the party was attacked.
"In the grey of the morning the look-outs reported the approach of three canoes with about ten men in each. On two or three persons shewing themselves in the bow of the pinnace, in front of the rain awning, the natives ceased paddling, as if baulked in their design of surprising the large boat; but, after a short consultation, they came alongside in their usual noisy manner. After a stay of about five minutes only they pushed off to the galley, and some more sham bartering was attempted, but they had nothing to give in exchange for the wares they so much coveted. In a short time the rudeness and overbearing insolence of the natives had risen to a pitch which left no doubt of their hostile intentions. The anchor was got up, when some of the blacks seized the painter, and others, in trying to capsize the boat, brought the gunwale down to the water's edge, at the same time grappling with the men to pull them out, and dragging the galley inshore towards the shoal-water. The bowman, with the anchor in his hand, was struck on the head with a stone-headed axe. The blow was repeated, but fortunately took effect only on the wash-streak. Another of the crew was struck at with a similar weapon, but warded off the blow, although held fast by one arm, when, just as the savage was making another stroke, Lieutenant Dayman, who up till now had exercised the utmost forbearance, fired at him with a musket. The man did not drop, although wounded in the thigh. But even this, unquestionably their first experience of firearms, did not intimidate the natives, one of whom, standing on a block of coral, threw a spear which passed across the breast of one of the boat's crew and lodged in the bend of one arm, opening a vein. They raised a loud shout when the spear was seen to take effect, and threw several others which missed. Lieutenant Simpson, who had been watching what was going on, then fired from the pinnace with buckshot and struck them, when, finding that the large boat, though at anchor, could assist the smaller one, the canoes were paddled inshore in great haste and confusion. Some more musket shots were fired, and the galley went in chase endeavouring to turn the canoes, so as to bring them under fire of the pinnace's twelve-pounder howitzer, which was speedily mounted and fired. The shot either struck one of the canoes or went within a few inches of the mark, on which the natives instantly jumped overboard into the shallow water, making for the mangroves, which they succeeded in reaching, dragging their canoes with them. Two rounds of grape-shot crashing through the branches dispersed the party, but afterwards they moved two of the canoes out of sight. The remaining one was brought out after breakfast by the galley under cover of the pinnace, and was towed off to some distance. The paddles having been taken out and the spears broken and left in her, she was let go to drift down toward a village whence the attacking party were supposed to have come. Some blood in this canoe, although not the one most aimed at, showed that the firing had not been ineffective. This act of deliberate treachery was perpetrated by persons who had always been well treated by us, for several of the natives present were recognised as having been alongside the ship in Coral Haven. This, their first act of positive hostility, affords, I think, conclusive evidence of the savage disposition of the natives of this part of the Louisiade Archipelago when incited by the hope of plunder, and shews that no confidence should ever be reposed in them, unless, perhaps in the presence of a numerically superior force, or in the close vicinity of a ship. At the same time, the boldness of these savages in attacking, with thirty men in three canoes, two boats known to contain at least twenty persons—even in the hopes of taking them by surprise—and in not being at once driven off upon feeling the novel and deadly effects of firearms, shews no little amount of bravery."
On their last visit to Cape York, in the extreme north of Australia, the party had the remarkable experience of rescuing a white woman from captivity among the natives.
"In the afternoon some of our people on shore were surprised to see a young white woman come up to claim their protection from a party of natives from whom she had recently made her escape, and who she thought would otherwise bring her back. Of course she received every attention, and was taken on board the ship by the first boat, when she told her story which is briefly as follows: Her name is Barbara Thomson. She was born at Aberdeen in Scotland, and, along with her parents, emigrated to New South Wales. About four years and a half ago she left Moreton Bay with her husband in a small cutter, called the America, of which he was the owner, for the purpose of picking up some of the oil from the wreck of a whaler, lost on the Bampton shoal, to which place one of her late crew undertook to guide them; their ultimate intention was to go on to Port Essington. The man who acted as pilot was unable to find the wreck, and after much quarreling on board in consequence, and the loss of two men by drowning and of another who was left on a small uninhabited island, they made their way up to the Torres Straits, where, during a gale of wind their vessel struck upon a reef on the eastern Prince of Wales Island. The two remaining men were lost in attempting to swim on shore through the surf, but the woman was afterwards rescued by a party of natives on a turtling excursion, who, when the gale subsided, swam on board and supported her on shore between two of their number. One of these blacks, Boroto by name, took possession of the woman as his share of the plunder; she was compelled to live with him, but was well treated by all the men, although many of the women, jealous of the attention shewn her, for a long time evinced anything but kindness. A curious circumstance secured for her the protection of one of the principal men of the tribe. This person, acting upon the belief, universal throughout Australia and the islands of the Torres Strait, so far as hitherto known, that white people are the ghosts of the aborigines, fancied that in the stranger he recognised a long-lost daughter, and at once admitted her into the relationship which he thought had formerly subsisted between them. She was immediately acknowledged by the whole tribe as one of themselves, thus securing an extensive connection in relatives of all denominations. The headquarters of the tribe being on an island which all vessels passing through the Torres Strait from the eastward must approach within two or three miles, she had the mortification of seeing from twenty to thirty or more ships go through every summer without anchoring in the neighbourhood, so as to afford the slightest opportunity of making her escape. Last year she heard of our two vessels being at Cape York, only twenty miles distant from some of the tribe who had communicated with us and had been well treated, but they would not take her over and watched her even more narrowly than before. On our second and present visit, however, which the Cape York people immediately announced by smoke signals to their friends, she was successful in persuading some of her more immediate friends to bring her across to the mainland within a short distance of where the vessels lay. The blacks were credulous enough to believe that as she had been so long with them and had been so well treated, she did not intend to leave them,—only 'she felt a strong desire to see the white people once more and shake hands with them': adding that she would be certain to purchase some axes, knives, tobacco, and other much-prized articles."
Although the external adventures of the Rattlesnake party were less varied and exciting than might have been expected in a voyage of four years in the tropic seas and among barbarian tribes, the mental adventures through which Huxley passed in the time must have been of the most surprising kind. It was a four-years' course in the great university of nature, and when he had finished it he was no longer a mere student, capricious and unsettled in his mental tastes and inclinations, but had set his face steadily towards his future life-work. It is interesting to compare the importance in Huxley's life of the Rattlesnake voyage with the importance in Darwin's life of the voyage on the Beagle undertaken some fifteen years earlier. Huxley, when he started, was a young surgeon with a taste of a vague kind for dissecting and for drawing the peculiarities of structure of different animals revealed by the knife and the microscope. Day after day, month after month, year after year, in the abundant leisure his slight professional duties left him, he dissected and drew, dissected and drew, animal after animal, as he got them from the dredge or tow-net, or from the surface of the coral reefs. He was not in any sense of the word a collecting naturalist. The identification and naming of species interested him little. What he cared for was, he tells us, "the architectural and engineering part of the business: the working out of the wonderful unity of plan in the thousands and thousands of divers living constructions, and the modifications of similar apparatuses to serve different ends." And so, on the Rattlesnake, and in his work in continuation of the Rattlesnake investigations,—which occupied most of his time for a few years after his return to London,—there was gradually growing up in his mind a dim conception of the animal kingdom as a group of creatures, not built on half a dozen or more separate plans or types, each unconnected with the other, but as a varied set of modifications of a single type.
When Darwin set out on the Beagle, unlike Huxley, he was an enthusiastic collecting naturalist. He had wandered from county to county in England adding new specimens to his collections of butterflies and beetles. As the Beagle went round the world visiting remote islands, far from land in the centre of the waters, archipelagoes of islands crowding together, islands hugging the shore of continents, and the great continents of the old and new worlds, he continued to collect and to classify. Gradually the resemblances and differences between the creatures inhabiting different parts of the earth began to strike him as exhibiting an orderly plan. He saw that under apparently the same conditions of food and temperature and moisture, in different parts of the world the genera and species were different, and that they were most alike in regions between which there was the most recent chance of migrations having taken place. In the quietness of England, while Huxley was on the Rattlesnake, Darwin was slowly working towards the explanation of all he had seen: towards the conception that animals and plants had spread slowly from common centres, becoming more and more different from each other as they spread. He realised on his voyage that species had come into existence by descent with modification, and before long he was to publish to the world in the Origin of Species a vast and convincing bulk of evidence as to the actual fact of a common descent for all the different existing organisms, and, in his theory of natural selection, a reasonable explanation of how the fact of evolution had come about. Darwin's greatest ally in bringing the new idea before the world was Huxley, and Huxley was teaching himself the absolute unity of the living world. The two men were dissimilar in tastes and temperament, and they were at work on quite different sides of nature. When the time came, Huxley, with his commanding knowledge of the structure of animals, was ready to support Darwin and to illustrate and amplify his arguments by a thousand anatomical proofs. It is a curious and dramatic coincidence to realise that both men learned their very different lessons under very similar circumstances in the tropical seas of the Southern Hemisphere.
FOOTNOTES:
[B] Narrative of the Voyage of H.M.S. "Rattlesnake," by John MacGillivray, F.R.G.S. 2 vols. T.W. Boone, London, 1852.
[C] This sketch was reproduced and described in Natural Science, vol. vii., p. 381, and is now reproduced here by the courtesy of the proprietors.
[CHAPTER III]
FLOATING CREATURES OF THE SEA
The Nature of Floating Life—Memoir on Medusæ Accepted by the Royal Society—Old and New Ideas of the Animal Kingdom—What Huxley Discovered in Medusæ—His Comparison of them with Vertebrate Embryos.
As the Rattlesnake sailed through the tropical seas Huxley came in contact with the very peculiar and interesting inhabitants of the surface of the sea, known now to naturalists as pelagic life or "plankton." Although a poet has spoken of the "unvintageable sea," all parts of the ocean surface teem with life. Sometimes, as in high latitudes, the cold is so great that only the simplest microscopic forms are able to maintain existence. In the tropics, animals and plants are abundant, and sometimes by their numbers colour great areas of water; or, as in the drift of the Gulf Stream, make a tangle of animal and plant life through which a boat travels only with difficulty. The basis of the food supply of this vast and hungry floating life is, as on land, vegetable life; for plants are the only creatures capable of building up food from the gases of the air and the simple chemical salts found dissolved in water. Occasionally, in shallow or warm seas, marine floating plants, large and visible like the sea-weeds of the coast, form the floating masses known as Sargasso seas; more often the plants are minute, microscopic specks visible only when a drop of water is placed under the microscope, but occurring in incredible numbers, and, like the green vegetation of the earth, forming the ultimate food-supply of all the living things around them. Innumerable animals, great and small, live on the plants or upon their fellows, and, however far he may be from land, the naturalist has always abundant material got by his daily use of the tow-net. This drifting population floats at the mercy of the waves. Most of the animals are delicate, transparent creatures, their transparency helping to protect them from the attacks of hungry fellows. Nerves, muscles, skin, and the organs generally are clear, pale, and hardly visible. Such structures as the liver, the reproductive organs, and the stomach, which cannot easily become transparent, are grouped together into small knots, coloured brown like little masses of sea-weed. Other floating creatures are vividly coloured, but the hues are bright blues and greens closely similar to the sparkling tints of sea-water in sunlight. The different members of this marine flotsam frequently rise and fall periodically: some of them sinking by day to escape the light, others rising only by day; others, again, appearing on the surface in spring, keeping deep down in winter. Perhaps the majority of them are phosphorescent, sometimes shining by their own light, sometimes borrowing a glory from innumerable phosphorescent bacteria with which they are infested. Nearly every class of the animal kingdom contributes members to this strange population. The young forms of many fish, as for instance of conger, flying gurnards, and some flatfish, are pelagic and have colourless blood, and pale, transparent, gelatinous or cartilaginous skeletons. The tadpole-like stages of the sea-squirts, which in adult life are to be found attached to rocks like weeds, drift about in the surface waters until their time comes for settling down in life. Many other Ascidians pass their whole life as pelagic creatures. A few molluscs, many kinds of worms, echinoderms, and their allies, crab and lobster-like creatures in innumerable different stages of development, are to be found there, while unnumbered polyps and jelly-fish are always present. It would be difficult to imagine a better training for the naturalist than to spend years, as Huxley did, working at this varied assortment of living creatures. Huxley declared that the difficulties of examining such flimsy creatures had been exaggerated.
"At least, with a good light and a good microscope, with the ship tolerably steady, I never failed in procuring all the information I required. The great matter is to obtain a good successive supply of specimens, as the more delicate oceanic species are usually unfit for examination within a few hours after they are taken."
Day after day, as the Rattlesnake crept from island to island, Huxley examined the animals brought up by his tow-net. He made endless dissections, and gradually accumulated a large portfolio of drawings. Much of the time he passed at Sydney was spent in libraries and museums, comparing his own observations with the recorded observations of earlier workers, and receiving from the combination of his own work and the work of others new ideas for his future investigations. It was all entirely a labour of love; it lay outside the professional duties by which he made his living, and for a long time it seemed as if he was not even to gain reputation by the discoveries he knew himself to be making. He writes in his autobiography:
"During the four years of our absence, I sent home communication after communication to the 'Linnæan' Society, with the same result as that obtained by Noah when he sent the raven out of his ark. Tired at last of hearing nothing about them, I determined to do or die, and in 1849 I drew up a more elaborate paper and forwarded it to the Royal Society. This was my dove, if I had only known it; but owing to the movements of the ship I heard nothing of that either until my return to England in the latter end of the year 1850, when I found that it was printed and published, and that a huge packet of separate copies awaited me. When I hear some of my young friends complain of want of sympathy and encouragement, I am inclined to think that my naval life was not the least valuable part of my education."
This first successful paper was a memoir On the Anatomy and the Affinities of the Family of Medusæ, and was sent at Captain Stanley's suggestion to that officer's father, the Bishop of Norwich, who communicated it to the Royal Society. It is a curious circumstance that Huxley, who afterwards met with so virulent opposition from bishops, owed his first public success to one of them. Professor Sir Michael Foster writes of this period in Huxley's life:
"The career of many a successful man has shewn that obstacles often prove the mother of endeavour, and never was this lesson clearer than in the case of Huxley. Working amidst a host of difficulties, in want of room, in want of light, seeking to unravel the intricacies of minute structure with a microscope lashed to secure steadiness, cramped within a tiny cabin, jostled by the tumult of a crowded ship's life, with the scantiest supply of books of reference, with no one at hand of whom he could take counsel on the problems opening up before him, he gathered for himself during these four years a large mass of accurate, important, and in most cases novel, observations and illustrated them with skilful, pertinent drawings. Even his intellectual solitude had its good effects: it drove him to ponder over the new facts which came before him, and all his observations were made alive with scientific thought."
Afterwards, in England, he received the Royal Medal of the Royal Society for this memoir on Medusæ, sharing this supreme distinction of scientific England with men so illustrious as Joule, the discoverer of the relation between force and heat, Stokes, the great investigator of optical physics, and Humboldt, the traveller, all of whom received medals in the same year. In making the presentation to Huxley, the Earl of Rosse, then President of the Royal Society, declared:
"In those papers you have for the first time fully developed their structure (that of the Medusæ), and laid the foundation of a rational theory for their classification. In your second paper, on the anatomy of Salpa and Pyrosoma, the phenomena have received the most ingenious and elaborate elucidations, and have given rise to a process of reasoning, the results of which can scarcely yet be anticipated, but must bear in a very important degree upon some of the most abstruse points of what may be called transcendental physiology."
Many reasons make it difficult for us to realise, now, the singular novelty and importance of Huxley's memoir on the Medusæ. The first is a reason which often prevents great discoveries in almost every subject from receiving in after years their due respect. The years that have passed since 1850 have seen not only the most amazing progress in our knowledge of comparative anatomy, but almost a revolution in the methods of studying it. Huxley's work has been incorporated in the very body of science. A large number of later investigators have advanced upon the lines he laid down; and just as the superstructures of a great building conceal the foundations, so later anatomical work, although it has only amplified and extended Huxley's discoveries, has made them seem less striking to the modern reader. The present writer, for instance, learned all that he knows of anatomy in the last ten years, and until he turned to it for the purpose of this volume he had never referred to Huxley's original paper. When he did so, he found from beginning to end nothing that was new to him, nothing that was strange: all the ideas in the memoir had passed into the currency of knowledge and he had been taught them as fundamental facts. It was only when he turned to the text-books of anatomy and natural history current in Huxley's time that he was able to realise how the conclusions of the young ship-surgeon struck the Fellows and President of the Royal Society as luminous and revolutionary ideas.
In the first half of the century, a conception of the animal kingdom prevailed which was entirely different from our modern ideas. We know now that all animals are bound together by the bond of a common descent, and we seek in anatomy a clue to the degrees of relationship existing among the different animals we know. We regard the animal kingdom as a thicket of branches all springing from a common root. Some of these spring straight up from the common root unconnected with their fellows. Others branch repeatedly, and all the branches of the same stem have features in common. What we see in the living world is only the surface of the thicket, the tops of the twigs; and it is by examination of the structure of this surface that we reconstruct in imagination the whole system of branches, and know that certain twigs, from their likeness, meet each other a little way down; that others are connected only very deep down, and that others, again, spring free almost from the beginning. The fossils of beds of rock of different geological ages give us incomplete views of the surface of the thicket of life, as it was in earlier times. These views we have of the past aspects of the animal kingdom are always much more incomplete than our knowledge of the existing aspect; partly because many animals, from the softness of their bodies, have left either no fossil remains at all, or only very imperfect casts of the external surfaces of their bodies; and partly because the turning of any animal into a fossil, and its subsequent discovery by a geologist, are occasional accidents; but, although the evidence is much less perfect than we could wish, there is enough of it to convince anatomists that existing animals are all in definite blood-relationship to each other, and to make them, in the investigation of any new animal, study its anatomy with the definite view of finding out its place in the family tree of the living world.
When Huxley made his first discoveries, entirely different ideas prevailed. The animal kingdom was supposed to offer a series of types, of moulds, into which the Creator at the beginning of the world had cast the substance of life. These types were independent of each other, and had been so since the beginning of things. Anatomists were concerned chiefly with systematic work, with detecting and recording the slight differences that existed among the numbers of animals grouped around each type. No attempt was made to see connection between type and type, for where these had been separately created there was nothing to connect them except possibly some idea in the mind of the Creator. This apparently barren attitude to nature was stronger in men's minds because it had inspired the colossal achievements of Cuvier, a genius who, under whatever misconceptions he had worked, would have added greatly to knowledge. As we have seen in the first chapter, Huxley, through Wharton Jones, and through his own reading, had been brought under the more modern German thought of Johannes Mueller and Von Baer. He had learned to study the problems of living nature in the spirit of a physicist making investigations into dead nature. In the anatomy of animals, as in the structure of rocks and crystals, there were to be sought out "laws of growth" and shaping and moulding influences which accounted for the form of the structures. To use the technical term, he was a morphologist: one who studied the architecture of animals not merely in a spirit of admiring wonder, but with the definite idea of finding out the guiding principles which had determined these shapes.
Not only was the prevailing method of investigation faulty, but actual knowledge of a large part of the animal kingdom was extremely limited. In the minds of most zoölogists the animal kingdom was divided into two great groups: the vertebrates and invertebrates. The vertebrate, or back-boned, animals were well known; comparatively speaking they are all built upon the type of man; and human anatomists, who indeed made up the greater number of all anatomists, using their exact knowledge of the human body, had studied many other vertebrates with minute care, and, from man to fishes, had arranged living vertebrates very much in the modern order. But the invertebrates were a vague and ill-assorted heap of animals. It was not recognised that among them there were many series of different grades of ascending complexity, and there was no well-known form to serve as a standard of comparison for all the others in the fashion that the body of man served as a standard of comparison for all vertebrates. Here and there, a few salient types such as insects and snails had been picked out, but knowledge of them helped but little with a great many of the invertebrates. The great Linnæus had divided the animal kingdom into four groups of vertebrates: mammals, birds, reptiles, and fishes, but for the invertebrates he had done no more than to pick out the insects as one group and to call everything else "Vermes" or worms. The insects included all creatures possessed of an external skeleton or hard skin divided into jointed segments, and included forms so different as insects, spiders, crabs, and lobsters. But Vermes included all the members of the animal kingdom that were neither vertebrates nor insects. Cuvier advanced a little. He got rid of the comprehensive title Vermes—the label of the rubbish-heap of zoölogists. He divided animals into four great subkingdoms: Vertebrates, Mollusca, Articulata, Radiata. These names, however, only covered very superficial resemblances among the animals designated by them. The word Mollusca only meant that the creatures grouped together had soft bodies, unsupported by internal or external articulated skeletons; and this character, or, rather, absence of character, was applied alike to many totally dissimilar creatures. The term Articulata included not only Linnæus's insects but a number of soft-skinned, apparently jointed, worm-like animals such as the leech and earthworm. Lastly, the name Radiata meant no more than that the organs of the creatures so designated were more or less disposed around a centre, as the sepals and petals of a flower are grouped around the central pistil; and it included animals so different as the starfish and sea-anemones and Medusæ. The names used in the classification were not only loosely applied but were based on the most superficial observation, and took no account of the intimate structures of the tissues and organs of the animals. With slight modifications, due to individual taste or special knowledge of small groups, later writers had followed Linnæus and Cuvier.
It was with a view of the animal kingdom not much clearer than this that Huxley began his work on the Medusæ of the tropic seas. He began to study them no doubt simply because they were among the most abundant of the animals that could be obtained from the ship. He made endless dissections and drawings, and, above all, studied their minute anatomy with the microscope. They were all placed among Cuvier's Radiata, but, as Huxley said in the first line of his memoir:
"Perhaps no class of animals has been investigated with so little satisfactory and comprehensive result, and this not for the want of patience and ability on the part of the observers, but rather because they have contented themselves with stating matters of detail concerning particular genera and species, instead of giving broad and general views of the whole class, considered as organised upon a given type, and inquiring into its relations with other families."
He found that fully developed Medusæ consisted each of a disc with tentacles and vesicular bodies at the margins, a stomach, and canals proceeding from it, and generative organs. He traced this simple common structure through the complications and modifications in which it appeared in the different groups of Medusæ, in all this work bringing out the prevailing features of the anatomy in contrast to the individual peculiarities. He shewed that microscopically all the complicated systems of canals and organs were composed of two "foundation-membranes," two thin webs of cells, one of which formed the outermost layer of the body, while the inner formed the lining of the stomach and canals in the thinner parts of the body, such as the edges of the umbrella-like disc, and towards the ends of the tentacles. These thin webs formed practically all the body. In the thicker parts there was interposed between them an almost structureless layer of jelly, placed like padding between the lining and the cloth of a coat. He shewed that blood-vessels and blood were absent, in which he has been confirmed by all other observers. He declared more doubtfully against the existence of a special nervous system, and it was not until long after, when the methods of microscopic investigation were much more perfect, that the delicate nerve-cells and nerve-fibres, which we now know to exist, were discovered.
Having thus shewn the peculiar organisation of the group he turned to seek out its allies among other families. The Medusæ consisted essentially of two membranes inclosing a variously shaped cavity inasmuch as all its organs were so composed. The generative organs were external, being variously developed processes of the two membranes. The peculiar organs called thread-cells—poisoned darts by the discharge of which prey could be paralysed—were universally present. What other families presented these peculiarities?
There are to be found abundantly in sea-water, and less frequently in fresh water, innumerable forms of animal life called Zoöphytes or animal plants because they occur as encrusting masses like lichens, or branched forests like moss, on the surface of stones and shells. A common habit gave this set of creatures their common name; but, although they were grouped together, there was no greater affinity among them than there is racial affinity among people who clothe themselves for an evening party in the same conventional dress. Huxley examined a large number of these, and picked out from them two great families of polyps, the Hydroid and Sertularian polyps, which each consist of colonies of creatures very much like the little fresh-water hydra. He shewed that the tubular body of these and the ring of tentacles surrounding the mouth were composed of the same two foundation-membranes of which all the organs of Medusæ are composed. He found in them the poisoned arrows or thread-cells of the Medusæ, and the same external position of the reproductive organs. And, lastly, he separated from all other creatures, and associated with his new group, some of the strangest and most beautiful animals of the tropic seas, known to science as the Physophoridæ and the Diphyidæ. The best-known of these is the "Portuguese man-of-war," the body of which consists of a large pear-shaped vesicle which floats on the water like a bladder. From the lower part of this depend into the water large and small nutritive branches, each ending in a mouth surrounded by a circle of waving tentacles armed with batteries of thread-cells, while another set of hanging protrusions bear the grape-like reproductive organs. On the upper surface of the bladder is fixed a purple sail of the most brilliant colour, by which the floating creature is blown through the water. When the weather is rough, the bladder empties, and the creature sinks down into the quiet water below the waves, to rise again when the storm is over. This, and its equally wonderful allies, Huxley showed to be a complicated colony of hydra-like creatures, each part being composed of two membranes, and therefore essentially similar to Medusæ. Thus, by a great piece of constructive work, an assemblage of animals was gathered into a new group and shewn to be organised upon one simple and uniform plan, and, even in the most complex and aberrant forms, reducible to the same type. The group, and Huxley's conception of its structure, are now absolutely accepted by anatomists, and have made one of the corner-stones of our modern idea of the arrangement of the animal kingdom. With the exception of sponges, concerning the exact relations of which there is still dispute, and of a few sets of parasitic and possibly degenerate creatures, all animals, the bodies of which are multicellular, from the simple fresh-water hydra up to man, are divided into two great groups. The structure of the simpler of these groups is exactly what Huxley found to be of importance in the Medusæ. The body wall, from which all the organs protrude, consists merely of a web of cells arranged in two sheets or membranes, and the single cavity consists of a central stomach, surrounded by these membranes, the cavity remaining simple or giving rise to a number of branching canals. The members of this great division of the animal kingdom are the creatures which Huxley selected and placed together, with the addition of the sea-anemones and the medusa-like Ctenophora, which, indeed, he mentioned in his memoir as being related to the others, but reserved fuller consideration for a future occasion. This group is now called the Cœlenterata, the name implying that the creatures are simply hollow stomachs, and it is contrasted in the strongest way with the group Cœlomata, in which are placed all the higher animals, from the simplest worm up to man; animals in which, in addition to the two foundation-membranes of the Cœlenterata, there is a third foundation-membrane, and in which, in addition to the simple stomach cavity with its offshoots, there is a true body-cavity or cœlome, and usually a set of spaces and channels containing a blood-fluid. The older method of naming groups of animals after some obvious superficial character lingered on for some years in text-books and treatises, but in this memoir the young ship-surgeon had replaced it by the modern scientific method of grouping animals together only because of real identity of structure.
There is yet left to be noticed perhaps the most wonderful of all the ideas in this first memoir by Huxley. In the course of describing the two foundation membranes of the Medusæ he remarks:
"It is curious to remark, that throughout, the outer and inner membranes appear to bear the same physiological relation to one another as do the serous and mucous layers of the germ: the outer becoming developed into the muscular system, and giving rise to the organs of offence and defence: the inner on the other hand appearing to be more closely subservient to the purposes of nutrition and generation."
In the whole range of science it would be difficult to select an utterance more prophetic of future knowledge than these few words. Huxley had been reading the investigations of Von Baer into the early development of back-boned animals. He had learned from them the great generalisation, that the younger stages of these animals resemble one another more closely than the adult stages, and that in an early stage in the development of all these animals the beginning of the embryo consists of two layers of cells, in fact of two foundation-membranes, one forming specially the wall of the future digestive canal, the other forming the most external portion of the future animal. In these days nothing could have seemed a remoter or more unlikely comparison than one instituted between Medusæ and the embryonic stages of back-boned animals. But Huxley made it, not allowing the evidence brought before his reason to be swamped by preconceived ideas. At the time he did no more than to make the comparison. It was much later that the full importance of it became known, when more extended work on the embryology of vertebrates and of the different groups of the invertebrates had made it plain that the two foundation-membranes of Huxley occur in all animals from the Medusæ up to man. In the group of Cœlenterata the organisation remains throughout life as nothing more than a folding in and folding out of these membranes. The early stages of all the higher animals similarly consist of complications of the two membranes; but later on there is added to them a third membrane. Thus the group that Huxley gathered together comprises those animals that as adults remain in a condition of development which is passed through in the embryonic life of all higher animals. The immense importance of this conclusion becomes plain, and the conclusion itself seems obvious, when seen in the light of the doctrine of descent. The group of Cœlenterata represents a surviving, older condition in the evolution of animals. Huxley himself, when on the Rattlesnake, regarded evolution only as a vague metaphysical dream, and he made the comparison which has been described without any afterthought of what it implied. In this we have the earliest authentic instance of the peculiar integrity of mind which was so characteristic of him in his dealings with philosophy and tradition. He never allowed any weight of authority or any apparent disturbance of existing ideas to alter the conclusions to which his reason led him. This intellectual courage made him fitted to be the leader in the battle for evolution and against traditional thought, and we shall find again and again in consideration of his work that it was the keynote of his life.
[CHAPTER IV]
EARLY DAYS IN LONDON
Scientific Work as Unattached Ship-Surgeon—Introduction to London Scientific Society—Translating, Reviewing, and Lecturing—Ascidians—Molluscs and the Archetype—Criticism of Pre-Darwinian Evolution—Appointment to Geological Survey.
The Rattlesnake was paid off at Chatham on November 9, 1850. In the natural course of events Huxley would have been appointed before long to active service upon another ship. But he had no intention of relapsing into the position of a mere navy doctor; he had accumulated sufficient scientific material to keep him employed on scientific investigation for years, and so he applied to the Admiralty to "be borne on the books" of H.M.S. Fisgard at Woolwich,—that is to say, to be appointed assistant-surgeon to the ship "for particular service," so that he should not be compelled to live on board, but might remain in town, and, with free access to libraries and museums, work up the observations he had made on the Rattlesnake into serious and substantial contributions to science. His request was granted, largely by the aid of his old chief, Sir W. Burnett, who continued to take the most useful interest in the young man he had originally nominated to the service. In a letter to him Huxley described the investigations which he desired to continue as being chiefly those on "the anatomy of certain Gasteropod and Pteropod Mollusca, of Firola and Atlantis, of Salpa and Pyrosoma, of two new Ascidians, namely, Appendicularia and Doliolum, of Sagitta and certain Annelids, of the auditory and circulatory organs of certain transparent Crustacea, and of the Medusæ and Polyps." His request was granted, and for the next three years Huxley lived in London with his brother, on the exiguous income of an assistant-surgeon, and devoted himself to research. He became almost at once of the first rank among English anatomists. The result of the paper on Medusæ in the Transactions of the Royal Society was that he was elected a Fellow of the Society on June 5, 1851, and a year later received a Royal Medal of the Society. He made many warm friendships both among the older and the younger generations of scientific men. In his obituary notice of Huxley, Sir Michael Foster wrote:
"By Edward Forbes, in whose nature there was much that was akin to his own, and with whom he had some acquaintance before his voyage, he was at once greeted as a comrade, and with Joseph Dalton Hooker, to whom he was drawn at the very first by their common experience as navy surgeons, he began an attachment which, strengthened by like biological aspirations, grew closer as their lives went on. In the first year after his return, in the autumn of 1851, he made the acquaintance of John Tyndall at the meeting of the British Association at Ipswich, and the three, Hooker, Huxley, and Tyndall, finding how much in common were all their scientific views and desires, formed then and there a triple scientific alliance."
Repeated efforts were made by these three, and by more influential friends, to induce the Admiralty to contribute to the expense of publishing Huxley's scientific results, as they had given a pledge to encourage officers who had done scientific work. These efforts lasted unavailingly for nearly three years, and then, as Huxley says: "The Admiralty, getting tired, I suppose, cut short the discussion by ordering me to join a ship, which thing I declined to do, and, as Rastignac, in the Père Goriot, says to Paris, I said to London, à nous deux." This light phrase conceals a courageous and momentous decision. He was absolutely without private resources, and having abandoned his professional work he had no salary of any kind. For a year or so he supported himself by writing reviews and popular scientific articles, striving all the time not only to gain his bread but to continue his scientific work and make it known to the public. He desired to get a professorship of physiology or of comparative anatomy, and as vacancies occurred he applied, but unsuccessfully. At the same time, he tells us, he and his friend, John Tyndall, were
"candidates, he for the Chair of Physics, and I for that of Natural History in the University of Toronto, which, fortunately, as it turned out, would not look at either of us. I say fortunately, not from any lack of respect for the University of Toronto; but because I soon made up my mind that London was the place for me, and hence I have steadily declined the inducements to leave it which have at various times been offered."
In these early years in London Huxley's work was most varied. A large number of anonymous articles by him appeared in the Literary Gazette, and in other periodicals. He assisted to remove the insular narrowness from English scientific work by translating many foreign memoirs. With the collaboration of Mr. Henfrey, he edited a series of scientific memoirs, all of which were translated from foreign languages, and many by his own pen. With the assistance of Mr. George Busk he made a translation of Kölliker's Histology, a great treatise on microscopic anatomy which played a large part in the development of the modern English schools of anatomy and physiology. He made some valuable contributions to Todd and Bowman's Cyclopædia of Anatomy, an elaborate publication now nearly forgotten and practically superseded, but which was the standard anatomical work of the middle of this century. He was unable to progress rapidly with his work upon oceanic Medusæ, as he was uncertain how to have it published; the Admiralty refused to assist, and it was too lengthy for publication in the volumes of the learned Societies. As a matter of fact, he did not publish it until 1858, when it appeared as a separate memoir. To the Quarterly Journal of Microscopical Science and to the Transactions of the Royal and Linnæan Societies he contributed a large number of memoirs dealing with the microscopic anatomy and relationships of invertebrates, and, lastly, he gave a series of addresses at the Royal Institution, which had been founded as a means by which leading men of science might give accounts of their work to London society. Abstracts of these lectures are published in the early volumes of the Proceedings of the Royal Institution and are interesting as shewing the kinds of zoölogical subjects which were attracting the attention of Huxley and which he considered of sufficient interest and importance to bring to the notice of the general public. The first of these lectures, and probably the first given in public by Huxley, occurred on April 30, 1852, and was entitled "Animal Individuality." The problem as to what is meant by an individual had been raised in his mind by consideration of many of the forms of marine life, notably compound structures like the Portuguese man-of-war, and creatures like the salps, which form floating chains often many yards in length. He explained that the word individual covers at least three quite different kinds of conceptions. There is, first, what he described as arbitrary individuality, an individuality which is given by the mind of the observer and does not actually exist in the thing considered. Thus a landscape is in a sense an individual thing, but only so far as it is a particular part of the surface of the earth, isolated for the time in the mind of the person looking at it. If the observer shift his position, the range of the landscape alters and becomes something else. Next there are material, or practically accidental individual things, such as crystals or pieces of stone; and, lastly, there are living individuals which, as he pointed out, were cycles. All living things are born into the world, grow up, and die, and it was to the cycle of life, from the egg to the adult which produces eggs, that he gave the name individual. In a simple animal like Hydra there is no difficulty in accepting this plain definition of individuality; but Huxley went on to compare with Hydra a compound creature like the Portuguese man-of-war, which really is composed of a colony of Hydra-like creatures, the different members of the colony being more or less altered to serve different functions. All these have come from the branching of a single simple creature produced from an egg, and to the whole colony Huxley gave the name of zoölogical individual. The salps give a still wider interpretation to this view of individuality. The original salp produced from the egg gives rise to many salps, which may either remain attached in a chain, or, breaking away from one another, may live separately. Huxley extended the use of the word individual so as to include as a single zoölogical individual the whole set of creatures cohering in chains or breaking apart, which had been produced by budding from the product of a single egg-cell. This subtle analysis of ideas delighted and interested his contemporaries, and the train of logical examination of what is meant by individuality has persisted to the present time. Like all other zoölogical ideas, this has been considerably altered by the conception of evolution. Zoölogists no longer attempt to stretch logical conceptions until they fit enormous and different parts of the living world. They recognise that the living world, because it is alive, is constantly changing, and that living things pass through different stages or kinds of individuality in the course of their lives. A single egg-cell is one kind, perhaps the simplest kind, of zoölogical individual; when it has grown up into a simple polyp it has passed into a second grade of individuality; when, by budding, the polyp has become branched, a third grade is reached, and when the branches have become different, in obedience to the different purposes which they are to serve in the whole compound creature, a still further grade is reached. Huxley's attempt to find a meaning for individuality that would apply equally to a single simple creature, to a compound creature, and to the large number of separate creatures, all developed by budding from one creature, is a striking instance of his singular capacity for bringing apparently dissimilar facts into harmony, by finding out the common underlying principle, and, although we no longer accept this particular conclusion, we cannot fail to notice in it the peculiar powers of his mind.
A second and even more interesting Royal Institution lecture dealt with the "Identity of Structure in Animals and Plants." At the present time every educated person knows that the life of animals and plants alike depends on the fact that their bodies are composed of a living material called protoplasm, a material which is identical in every important respect in both kingdoms of the living world. In the early fifties, scientific opinion was by no means clear on this matter, and certainly public opinion was most vague. Huxley discussed what was meant by organisation, and shewed that in every essential respect plants and animals alike were organised beings. Then he went on to explain the cellular theory of Schwann, which was then a novelty to a general audience. Schwann, in studying the microscopic structure of plants, noticed that their bodies were made up of little cases with firm walls; these he called cells, and declared that the whole body of the plant was composed of cells. As the walls of these cells were the most obvious and visible feature, it was supposed that they were the most essential part of the structure, and there was some difficulty in applying the cellular theory to the bodies of animals, as in most cases there are no easily visible cell-walls in animal tissues. As the result of his own observation, and from his reading of the work of others, Huxley laid down in the clearest way what is now accepted by everyone—that the presence of walls is of minor importance, and that it is the slimy contents of the cells, what is called "protoplasm," that is the important element. He declared that the protoplasm of animals was identical with the protoplasm of plants, and that plants were "animals confined in wooden cases." He agreed with Schwann that the cell, using the term to imply the contents rather than the wall, was of fundamental importance, and was the unit of structure of the whole world of life. On the other hand, he declared that it could not be looked at as the unit of function: he denied that the powers and properties of a living body were simply the sum of the powers and properties of the single cells. In this opinion he was not followed by physiologists until quite recently. For many years physiologists held that cells were units of function just as much as they are units of structure; but in the last ten years there has been a strong return to the opinion of Huxley.
In 1851 two very important memoirs were published in the Transactions of the Royal Society, which contained the results of Huxley's observations of the interesting animals known as "tunicates." The first of these papers begins as follows:
"The Salpæ, those strange gelatinous animals, through masses of which the voyager in the great ocean sometimes sails day after day, have been the subject of a great controversy since the time of the publication of the celebrated work of Chamisso, De Animalibus Quibusdam e Classe Vermium Linnæana. In this work there were set forth, for the first time, the singular phenomena presented by the reproductive processes of these animals,—phenomena so strange, and so utterly unlike anything then known to occur in the whole province of zoölogy, that Chamisso's admirably clear and truthful account was received with almost as much distrust as if he had announced the existence of a veritable Peter Schlemihl."
According to Chamisso, salps appeared in two forms: solitary forms, and forms in which a number of salps are united into a long chain. Each salp of the aggregate form contains within it an embryo receiving nutrition from the mother by a connection similar to the placenta by which the embryo of a mammal receives nourishment from the blood of the mother. These embryos grow up into the solitary form, and the solitary form gives rise to a long chain of the aggregate form which developes in the interior of the body. Chamisso compared this progress to the development of insects. "Supposing," he said, "caterpillars did not bodily change into butterflies, but by a process of sexual breeding produced young which grew into the ordinary adults, and that these adults, as indeed they do, gave rise to caterpillars by sexual reproduction, then there would be a true alternation of generations." The first generation would give rise to a second generation totally unlike itself, and this second generation would reproduce, not its kind, but the first generation; such an alternation of generations he stated to occur among the salps. Huxley had an excellent opportunity to study this question at Cape York in November, 1849. "For a time the sea was absolutely crowded with Salpæ, in all stages of growth, and of size very convenient for examination." He was able to verify the general truth of Chamisso's statement. The aggregate form of Salpa always gives rise to the solitary salps, and the solitary salps always give rise to chains of the aggregate salps. But the process of reproduction he shewed to be quite different in the two cases. The solitary salp produces in its interior a little stolon or diverticulum which contains an outgrowth from the circulatory system, and this stolon gradually becomes pinched off into the members of the chain of the aggregate form. The salps of the aggregate form are therefore merely buds from the solitary form, and are not produced in the ordinary way, by sexual generation. On the other hand, each salp of the chain has within it a true egg-cell. This is fertilised by a male cell, and within the body of the parent, nourished by the blood of the parent, grows up into the solitary form. There is then an alternation of generations, but there are not two sexual generations. The sexual generation of chain salps gives rise to forms which reproduce by buds. From this conclusion, with which all later observers have agreed, Huxley went on to his theory of individuality. Different names had been given to the two forms, but Huxley declared that neither form was a true zoölogical individual; they were only parts of individuals or organs, and the true individual was the complete cycle involving both forms.
In addition to determining the interesting method of reproduction, Huxley made an elaborate investigation of the structure of Salpa. On one occasion only the Rattlesnake came across a quantity of an allied Ascidian, Pyrosoma, which had received its name from its phosphorescence.
"The sky was clear but moonless, and the sea calm; and a more beautiful sight can hardly be imagined than that presented from the deck of the ship as she drifted, hour after hour, through this shoal of miniature pillars of fire gleaming out of the dark sea, with an ever-waning, ever brightening, soft bluish light, as far as the eye could reach on every side. The Pyrosomata floated deep, and it was only with difficulty that some were procured for examination and placed in a bucketful of sea-water. The phosphorescence was intermittent, periods of darkness alternating with periods of brilliancy. The light commenced in one spot, apparently on the surface of one of the zoöids, and gradually spread from this as a centre in all directions; then the whole was lighted up: it remained brilliant for a few seconds, and then gradually faded and died away, until the whole mass was dark again. Friction at any point induces the light at that point, and from thence the phosphorescence spreads over the whole, while the creature is quite freshly taken; afterwards, the illumination arising from friction is only local."
Dealing with these creatures in the broad anatomical spirit with which he had studied the Medusæ, Huxley shewed the typical structure manifested in the different forms, and that was common to them and the Ascidians or sea-squirts of the seashore. In a second paper on "Appendicularia and Doliolum" he made further contributions to our knowledge of these interesting creatures. Appendicularia is a curious little Ascidian, differing from all the others in its possession of a tail. Earlier observers had obtained it on various parts of the ocean surface, but had failed entirely to detect its relationship to the ordinary Ascidians. Chamisso got it near Behring's Straits and thought that it was more nearly allied to "Venus's Girdle," a Cœlenterate. Mertens, another distinguished zoölogist, had declared that "the relation of this animal with the Pteropods (a peculiar group of molluscs) is unmistakable"; while Müller, a prince among German anatomists, confessed that "he did not know in what division of the animal kingdom to place this creature." Huxley shewed that it possessed all the characteristic features of the Ascidians, the same arrangement of organs, the same kind of nervous system, a respiratory chamber formed from the fore part of the alimentary canal, and a peculiar organ running along the pharynx which Huxley called the endostyle and which is one of the most striking peculiarities of the whole group. The real nature of the tail was Huxley's most striking discovery. He pointed out that ordinary Ascidians begin life as tiny tadpole-like creatures which swim freely by the aid of a long caudal appendage; and that while these better-known Ascidians lose their tails when they settle down into adult life, the Appendiculariæ are Ascidians which retain this larval structure throughout life. Von Baer had shown that in the great natural groups of higher animals some forms occur which typify, in their adult condition, the larval state of the higher forms of the group. Thus, among the amphibia, frogs have tails in the larval or tadpole condition; but newts throughout life remain in the larval or tailed condition. Appendicularia he considered to be the lowest form of the Ascidians, and to typify in its adult condition the larval stages of the higher Ascidians.
By this remarkable investigation of the structure of the group of Ascidians, and display of the various grades of organisation, Huxley paved the way for one of the great modern advances in knowledge. When, later on, the idea of evolution was accepted, and zoölogists began hunting out the pedigree of the back-boned animals, it was discovered that Ascidians were modern representatives of an important stage in the ancestry of vertebrate animals, and, therefore, of man himself. There are few more interesting chapters in genealogical zoölogy than those which reveal the relationship between Amphioxus and fish on the one hand, and Ascidians on the other; for fish are vertebrates, and Ascidians, on the old view, are lowly invertebrates. The details of these relationships have been made known to us by the brilliant investigations of several Germans, by Kowalevsky, a Russian, by the Englishmen Ray Lankester and Willey, and by several Americans and Frenchmen. But behind the work of all these lies the pioneer work of Huxley, who first gathered the group of Ascidians together, and in a series of masterly investigations described its typical structure.
Huxley's next great piece of work was embodied in a memoir published in the Transactions of the Royal Society in 1853, and which remains to the present day a model of luminous description and far-reaching ideas. It was a treatise on the structure of the great group of molluscs, and displays in a striking fashion his method of handling anatomical facts, and deducing from them the great underlying principles of construction. The shell-fish with which he dealt specially were those distinguished as cephalous, because, unlike creatures such as the oyster and mussel, they had something readily comparable with the head of vertebrates. He began by pointing out what problems he hoped to solve. The anatomy of many of the cephalous molluscs was known, but the relation of structures present in one to structures present in another group had not been settled.
"It is not settled whether the back of a cuttle-fish answers to the dorsal or ventral surface of a gasteropod. It is not decided whether the arms and funnels of the one have or have not their homologues in the other. The dorsal integument of a Doris and the cloak of a whelk are both called 'mantle,' without any evidence to show that they are really homologous. Nor do very much more definite notions seem to have prevailed with regard to the archetypal molluscous form, and the mode in which (if such an archetype exist) it becomes modified in the different secondary types."
He had taken from the surface of the sea a number of transparent shell-fish, and had been able to study the structure and arrangement of their organs "by simple inspection, without so much as disturbing a single beat of their hearts." From knowledge gained in this fashion, and from ordinary dissection of a number of common snails, cephalopods, and pteropods, he was able to describe in a very complete way the anatomical structure of cephalous molluscs. The next natural step, he stated, would have been to describe the embryonic development of the organs of these different creatures in order that a true knowledge might be gained of what were the homologous or really corresponding parts in each. Having had no opportunity to make such embryological studies for himself, he fell back on numerous accounts of development by Kölliker, Van Beneden, Gegenbauer, and others, and so gradually arrived at a conception of what he called the "archetype" of the cephalous molluscs. As the word archetype was borrowed from old metaphysical ideas dating back to the time of Plato, he took care to state that what he meant by it was no more than a form embodying all that could be affirmed equally respecting every single kind of cephalous mollusc, and by no means an "idea" upon which it could be supposed that animal forms had been modelled. He described this archetype, and showed the condition of the different systems of organs which it could be supposed to possess, and how these organs were modified in the different existing groups. This archetypal mollusc of Huxley's was a creature with a bilaterally symmetrical head and body. On the ventral side of the body it possessed a peculiar locomotor appendage, the so-called foot, and the dorsal surface of the body secreted a shell. Its nervous system consisted of three pairs of ganglia or brains, one pair in the head, one in the foot, and a third in the viscera. He shewed how the widely different groups of cephalous molluscs could be conceived as modifications of this structure, and extended the conception so as to cover all other molluscs.
Quite apart from the anatomical value of this paper, and although all technical details have been omitted here, it is necessary to say that merely as a series of intricate anatomical descriptions and comparisons, this memoir was one of the most valuable of any that Huxley wrote. The working out of the theory of the archetype is peculiarly interesting to compare with modern conceptions. To those of us who began biological work after the idea of evolution had been impressed upon anatomical work, it is very difficult to follow Huxley's papers without reading into them evolutionary ideas. In the article upon Mollusca, written for the ninth edition of the Encyclopædia Britannica, by Professor Ray Lankester, the same device of an archetypal or, as Lankester calls it, a schematic mollusc, is employed in order to explain the relations of the different structures found in different groups of molluscs to one another. Lankester's schematic mollusc differs from Huxley's archetypal mollusc only as a finished modern piece of mechanism, the final result of years of experiment, differs from the original invention. The method of comparing the schematic mollusc with the different divergent forms in different groups is identical, and yet, while the ideas of Darwin are accepted in every line of Lankester's work, Huxley was writing six years before the publication of The Origin of Species. There was growing up in Huxley's mind, partly from his own attempts to arrange the anatomical facts he discovered in an intelligible series, the idea that within a group the divergencies of structure to be found had come about by the modification of an original type. Not only did he conceive of such an evolution as the only possible explanation of the facts, but he definitely used the word evolution to convey his ideas. On the other hand, he was firmly convinced that such evolution was confined within the great groups. For each group there was a typical structure, and modifications by defect or excess of the parts of the definite archetype gave rise to the different members of the group. Moreover, he confined this evolution in the strictest possible way to each group; he did not believe that what was called anamorphosis—the transition of a lower type into a higher type—ever occurred. To use his own words:
"If, however, all Cephalous Mollusca, i.e., all Cephalopoda, Gasteropoda, and Lamellibranchiata, be only modifications by excess or defect of the parts of a definite archetype, then, I think, it follows as a necessary consequence, that no anamorphosis takes place in this group. There is no progression from a lower to a higher type, but merely a more or less complete evolution of one type. It may indeed be a matter of very grave consideration whether true anamorphosis ever occurs in the whole animal kingdom. If it do, then the doctrine that every natural group is organised after a definite archetype, a doctrine which seems to me as important for zoölogy as the theory of definite proportions for chemistry, must be given up."
It is of great historical interest to notice how closely actual consideration of the facts of the animal kingdom took zoölogists to an idea of evolution, and yet how far they were from it as we hold it now. It is fashionable at the present time to attempt to depreciate the immense change introduced by Darwin into zoölogical speculation, and the method employed is largely partial quotation, or reference to the kind of ideas found in papers such as this memoir by Huxley. The comparison between the types of the great groups and the combining proportions of the chemical elements shows clearly that Huxley regarded the structural plans of the great groups as properties necessary and inherent in these groups, just as the property of a chemical element to combine with another chemical substance only in a fixed proportion is necessary and inherent in the existing conception of it. There was no glimmer of the idea that these types were not inherent, but merely historical results of a long and slow series of changes produced by the interaction of the varied conditions of life and the intrinsic qualities of living material.
In two lectures delivered at the Royal Institution in 1854 and 1855, the one on "The Common Plan of Animal Forms," the other on "The Zoölogical Arguments Adduced in Favour of the Progressive Development of Animal Life in Time," show, so far as the published abstracts go, the same condition of mind. The idea of progressive development of all life from common forms was not unknown to Huxley and his contemporaries, but was rejected by them. In the first of these two lectures he took four great groups of animals, the Vertebrates, the Articulata, the Mollusca, and the Radiata, and explained what was the archetype of each. He shewed the distinctiveness of each plan of structure, and then discussed the relations of the ideas suggested by Von Baer to these archetypes. He stated explicitly that while the adult forms were quite unlike one another, there were traces of a common plan to be derived from a study of their embryonic development. Such a trace of a common plan he had himself suggested when he compared the foundation-membranes of the Medusæ with the first foundation-membranes of vertebrate embryos. This was going a long way towards modern ideas; but he stopped short, and gave no hint that he believed in the possibility of the development of one plan from a lower or simpler plan. The second lecture dealt with the kind of ideas which were crystallised in the popular but striking work of Chambers, entitled Vestiges of Creation. Chambers attacked the theological view that all animals and plants had been created at the beginning of the world, and maintained that geological evidence showed the occurrence of a progressive development of animal life. Huxley, like all zoölogists and geologists who knew anything of the occurrence of fossils in the rocks of past ages, agreed with the general truth of the conception that a progressive development had occurred which showed that the species now existing were represented in the oldest rocks by species now extinct. But the examples he brought forward were all limited to evolution within the great groups, and did not affect his idea that archetypes were fixed and did not pass into each other. Moreover, he summed up strongly against the suggestion that there was any parallel between the succession of life in the past and the forms assumed by modern animals in their embryological development. So far as the present writer is able to judge from study of the literature of this period, the possibility of evolution was present in an active form in the minds of Huxley and of his contemporaries, and in an extraordinary way they brought together evidence which afterwards became of firstrate importance; but the idea in its modern sense was rejected by them.
In 1854 Huxley's uncomfortable period of probation came to an end. Edward Forbes, who held the posts of Palæontologist to the Geological Survey, and Lecturer on General Natural History at the Metropolitan School of Science Applied to Mining and the Arts, vacated these on his appointment to the Chair of Natural History in the University of Edinburgh, and Sir H. De La Beche, the then Director-General of the Geological Survey, offered both the posts to Huxley—who in June and July of that year had given lectures at the school in place of Forbes. Huxley says himself:
"I refused the former point-blank, and accepted the latter only provisionally, telling Sir Henry that I did not care for fossils, and that I should give up natural history as soon as I could get a physiological post. But I held the office for thirty-one years, and a large part of my work has been palæontological."
The salary of the post of Lecturer on Natural History was scanty, but De La Beche, who evidently recognised Huxley's genius, and was anxious to have him attached even against his will to palæontological work, created a place for him as Naturalist to the Geological Survey, by which a more suitable income was found for him. His official duties were at first in the Geological Museum of the Survey, but were distinguished from those of the special Palæontologist, Mr. Harvey. His income was now assured, and for the rest of his life, until towards its close, when he retired to Eastbourne, he lived the ordinary life of a professional man of science in London. He was now able to marry, and on July 21, 1855, he was married to a lady whom he had met in Sydney in 1847, and whom he had not seen since the Rattlesnake left Sydney finally in the beginning of May, 1850.
During the years 1856, 1857, and 1858, he held the post of Fullerian Professor of Physiology in the Royal Institution, choosing as the title of his first two courses of lectures Physiology and Comparative Anatomy, as he still cherished the idea of being in the first place a physiologist.
THOMAS HENRY HUXLEY, 1857
Reproduced by permission from Natural Science, vol. vii., No. 42
"Moreover," writes Professor Michael Foster, "like most other young professional men of science, he had to eke out his not too ample income by labours undertaken chiefly for their pecuniary reward. He acted as examiner, conducting for instance, during the years 1856 to 1863, and again 1865 to 1870, the examinations in physiology and comparative anatomy at the University of London, making even an examination paper feel the influence of the new spirit in biology; and among his examinees at that time there was at least one who, knowing Huxley's writings, but his writings only, looked forward to the viva voce test, not as a trial but as an occasion of delight. He wrote almost incessantly for all editors who were prepared to give adequate pay to a pen able to deal with scientific themes in a manner at once exact and popular, incisive and correct. During this period he was gradually passing from his first anatomical love, the structure of the Invertebrates, to Vertebrate work, and although he continued to take a deep interest in the course of the progress of research in that group of animals, the publication of his great work on oceanic hydrozoa by the Ray Society was the last piece of important work he wrote upon any anatomical subject apart from vertebrates. His work in connection with the Geological Survey naturally attracted his attention most closely to vertebrates, and, towards the close of the fifties, he was led to make a special study of vertebrate embryology, a subject which the investigations of Kölliker and others in Germany were bringing into prominence. The first result of this new direction of his enquiries was embodied in a Croonian Lecture delivered in 1858 'On the Theory of the Vertebrate Skull.' Sir Richard Owen, who was at that time the leading vertebrate anatomist in England, had given his support to an extremely complicated view of the skull as being formed of a series of expanded vertebræ moulded together. The theory was really a legacy from an old German school of which the chief members were Goethe, the poet, and Oken, a naturalist, who was more of a metaphysical philosopher than of a morphologist. Huxley pointed out the futility of attempting to regard the skull as a series of segments, and of supporting this view by trusting to superficial resemblances and abstract reasoning, when there was a definite method by which the actual building up of the skull might be followed. Following the lines laid down by Rathke, another of the great Germans from whose investigations he was always so willing to find corroboration and assistance in his own labours, he traced the actual development of the skull in the individual. He shewed that the foundations of the skull and of the backbone were laid down in a fashion quite different, and that it was impossible to regard both skull and backbone as modifications of a common type laid down right along the axis of the body. The spinal column and the skull start from the same primitive condition, whence they immediately begin to diverge. It may be true to say that there is a primitive identity of structure between the spinal or vertebral column and the skull; but it is no more true that the adult skull is a modified vertebral column than it would be to affirm that the vertebral column is a modified skull."
Since this famous lecture, a number of distinguished anatomists have studied the development of the skull more fully; but they have not departed from the methods of investigation laid down by Huxley, and their conclusions have differed only in greater elaboration of detail from the broad lines laid down by him. Apart from its direct scientific value, this lecture was of importance as marking the place to which Huxley had attained in the scientific world. Two years later, it is true, the London Times, referring to a famous debate at a meeting of the British Association at Oxford, spoke of him as "a Mr. Huxley"; but in the scientific world he was accepted as the leader of the younger anatomists, and as one at least capable of rivalling Owen, who was then at the height of his fame. The Croonian Lecture was in a sense a deliberate challenge to Owen, and in these days before Darwin, to challenge Owen was to claim equality with the greatest name in anatomical science.
[CHAPTER V]
CREATURES OF THE PAST
Beginning Palæontological Work—Fossil Amphibia and Reptilia—Ancestry of Birds—Ancestry of the Horse—Imperfect European Series Completed by Marsh's American Fossils—Meaning of Geological Contemporaneity—Uniformitarianism and Catastrophism Compared with Evolution in Geology—Age of the Earth—Intermediate and Linear Types.
Although Huxley took a post connected with Geology only because it was the most convenient opening for him, it was not long before he became deeply interested not only in the fossils, which at first he despised, but in the general problems of geology. He began by co-operation with Mr. Salter in the determination of fossils for the Geological Survey. The mere work of defining genera and species and naming and describing new species appealed very little to him. He had none of the collector's passion for new species; his interest in a creature being not whether or no it was new to science, but what general problems of biology its structure helped to elucidate. While he assisted in the routine work of determining the zoölogical position of the fossils sent in to the museum by the Survey, he carried investigations much farther than the duties of the post required when interesting zoölogical problems arose. His earliest notes were written in association with his colleague, and consisted of technical descriptions of some small fossils from the Downton Sandstones which were supposed to be fish-shields. The peculiarities of structure presented by these aroused his interest, and he began an elaborate series of investigations upon palæozoic fishes in general. Earlier zoölogists, such as the great Agassiz, had devoted most of their attention to careful and exact description of the different fossil fishes with which they became acquainted. Huxley at once began to investigate the relations that existed among the different kinds of structure exhibited in the different fish. He laid down the lines upon which future work has been conducted, and, precisely as he did in the case of molluscs, he started future investigators upon lines of research the ends of which have not yet been reached. His work upon Devonian Fishes, published in 1861, threw an entirely new light upon the affinities of these creatures, and still remains a standard work.
He made a similar, although less important, series of investigations upon some of the great extinct Crustacea; but, perhaps, his most important palæontological work was done later, after he had been convinced by Darwin of the fact of evolution. In 1855 he had expressed the opinion that the study of fossils was hopeless if one sought in it confirmation of the doctrine of evolution; but five-and-twenty years' continuous work completely reversed his opinion, and in 1881, addressing the British Association at York he declared that "if zoölogists and embryologists had not put forward the theory, it would have been necessary for palæontologists to invent it." In three special groups of animals his study of fossils enabled him to assist in bridging over the gaps between surviving groups of creatures by study of creatures long extinct. He began to study the structure of the Labyrinthodonts, a group of extinct monsters which received their name from the peculiar structure of their teeth. He published elaborate descriptions of Anthracosaurus from the coal-measures of Northumberland, of Loxomma from the lower carboniferous of Scotland, and of several small forms from the coal-measures of Kilkenny, in Ireland, as well as describing skulls from Africa and a number of fragmentary bones from different localities. But in all this work it was the morphology of the creatures that interested him, and the light which their structure threw upon the structure of each other and of their nearest allies. He shewed that these monsters stood on the borderland between fishes, amphibia, and reptiles, and he added much to our knowledge of the true structure of these great groups. Next, he turned to the extinct reptiles of the Mesozoic age. It was generally believed that the Pterodactyls, or flying reptiles, were the nearest allies of birds, but Huxley insisted that the resemblances between the wings were simply such superficial resemblances as necessarily exist in organs adapted to the same purpose. About the same time, Cope in America, and Phillips and Huxley, in England, from study of the bones of the Dinosaurs, another great group of extinct reptiles, declared that these were the nearest in structure to birds. In association with the upright posture, the ilium or great haunch-bone of birds extends far forwards in front of the articulation of the thigh-bone, so that the pelvis in this region has a T-shape, the ilium forming the cross-bar of the T, and the femur or thigh-bone the downward limb. Huxley shewed that a large number of the Dinosaurs had this and other peculiarities of the bird's pelvis, and separated these into a group which he called the "Ornithoscelida," seeing in them the closest representatives of the probable reptilian ancestors of birds. While further work and the discovery of a still greater number of extinct reptiles has made it less probable that these were the actual ancestors of birds, Huxley's work in this, as in the many other cases we have shown, proved not only of great value in itself, but led to a continually increasing series of investigations by others. It is not always the pioneer that makes the greatest discoveries in a new country, but the work of the pioneer makes possible and easier the more assured discoveries of his followers.
A third great piece of palæontological investigation with which the name of Huxley will always be associated, is the most familiar of all the instances taken from fossils in support of the evolution of animals. This famous case is the pedigree of the horse. In 1870, in an address delivered to the Geological Society of London, Huxley had shewn that there was a series of animals leading backwards from the modern horse to a more generalised creature called Anchitherium, and found in the rocks of the Miocene period. He suggested that there were, no doubt, similar fossils leading still further backwards towards the common mammalian type of animal, with five fingers and five toes, and went the length of suggesting one or two fossils which might stand in the direct line of ancestry. But in 1876 he visited America, and had the opportunity of consulting the marvellous series of fossils which Professor Marsh had collected from American Tertiary beds. Professor Marsh allowed him the freest use of his materials and of his conclusions, and the credit of the final result is to be shared at least equally between Marsh and Huxley. The final result was a demonstrative proof of the possible course of evolution of the horse, given in a lecture delivered by Huxley in New York on Sept. 22, 1876, and illustrated by drawings from specimens in Marsh's collection. The matter of the lecture has become so important a part of all descriptive writing on evolution, and the treatment is so characteristic of Huxley's brilliant exposition, that it is worth while to make some rather long quotations from it. The lecture was published in the New York papers, and afterwards with other matter formed a volume of American Addresses, published by Macmillan, in London.
"In most quadrupeds, as in ourselves, the forearm contains distinct bones called the radius and the ulna. The corresponding region in the horse seems at first to possess but one bone. Careful observation, however, enables us to distinguish in this bone a part which clearly answers to the upper end of the ulna. This is closely united with the chief mass of the bone which represents the radius, and runs out into a slender shaft which may be traced for some distance downwards on the back of the radius, and then in most cases thins out and vanishes. It takes still more trouble to make sure of what is nevertheless the fact, that a small part of the lower end of the bone of the horse's forearm, which is only distinct in a very young foal, is really the lower extremity of the ulna.
"What is commonly called the knee of a horse is its wrist. The 'cannon bone' answers to the middle bone of the five metacarpal bones which support the palm of the hand in ourselves. The 'pastern,' 'coronary,' and 'coffin' bones of veterinarians answer to the joints of our middle fingers, while the hoof is simply a greatly enlarged and thickened nail. But, if what lies below the horse's 'knee' thus corresponds to the middle finger in ourselves, what has become of the four other fingers or digits? We find in the places of the second and fourth digits only two slender splint-like bones, about two-thirds as long as the cannon bone, which gradually taper to their lower ends and bear no finger joints, or, as they are termed, phalanges. Sometimes small bony or gristly nodules are to be found at the bases of these two metacarpal splints, and it is probable that these represent rudiments of the first and fifth digits. Thus the part of the horse's skeleton which corresponds with that of the human hand contains one overgrown middle digit, and at least two imperfect lateral digits; and these answer, respectively, to the third, the second, and the fourth digits in man.
"Corresponding modifications are found in the hind limb. In ourselves, and in most quadrupeds, the leg contains two distinct bones, a large bone, the tibia, and a smaller and more slender bone, the fibula. But, in the horse, the fibula seems, at first, to be reduced to its upper end; a short slender bone united with the tibia and ending in a point below occupying its place. Examination of the lower end of a young foal's shin-bone, however, shews a distinct portion of osseous matter, which is the lower end of the fibula; so that the apparently single lower end of the shin-bone is really made up of the coalesced ends of the tibia and fibula, just as the apparently single lower end of the fore-arm bone is composed of the coalesced radius and ulna.
"The heel of the horse is the part commonly known as the hock; the hinder cannon bone answers to the middle metatarsal bone of the human foot, the pastern, coronary, and coffin bones, to the middle-toe bones; the hind hoof to the nail, as in the fore foot. And, as in the fore foot, there are merely two splints to represent the second and fourth toes. Sometimes a rudiment of a fifth toe appears to be traceable."
Having in the same fashion described the highly complicated and peculiar structure of the teeth of modern horses, Huxley proceeded:
"To anyone who is acquainted with the morphology of vertebrated animals, these characteristic structures of the horse show that it deviates widely from the general structure of mammals; and that the horse type is, in many respects, an extreme modification of the general mammalian plan. The least modified mammals, in fact, have the radius and ulna, the tibia and fibula, distinct and separate. They have five distinct and complete digits on each foot, and no one of these digits is very much larger than the rest. Moreover, in the least modified mammals, the total number of the teeth is very generally forty-four, while in the horse the usual number is forty, and, in the absence of the canines, it may be reduced to thirty-six; the incisor teeth are devoid of the fold seen in those of the horse; the grinders regularly diminish in size from the middle of the series to its front end; while their crowns are short, early attain their full length, and exhibit simple ridges or tubercles, in place of the complex foldings of the horse's grinders.
"Hence the general principles of the hypothesis of evolution lead to the conclusion that the horse must have been derived from some quadruped which possessed five complete digits on each foot; which had the bones of the forearm and of the leg complete and separate; and which possessed forty-four teeth, among which the crown of the incisors and grinders had a simple structure; while the latter gradually increased in size from before backwards, at any rate in the anterior part of the series, and had short crowns.
"And if the horse had been thus evolved, and the remains of the different stages of its evolution have been preserved, they ought to present us with a series of forms in which the number of the digits becomes reduced; the bones of the forearm and leg gradually take on the equine condition; and the form and arrangement of the teeth successively approximate to those which obtain in existing horses.
"Let us turn to the facts and see how far they fulfill these requirements of the doctrine of evolution.
"In Europe abundant remains of horses are found in the Quaternary and later Tertiary strata as far as the Pliocene formation. But these horses, which are so common in the cave-deposits and in the gravel of Europe, are in all essential respects like existing horses, and that is true of all the horses of the later part of the Pliocene epoch. But, in the deposits which belong to the earlier Pliocene, and later Miocene epochs, and which occur in Britain, in France, in Germany, in Greece, in India, we find animals which are extremely like horses—which in fact are so similar to horses, that you may follow descriptions given in works upon the anatomy of the horse, upon the skeletons of these animals—but which differ in some important particulars. For example, the structure of their fore and hind limbs is somewhat different. The bones, which, in the horse are represented by two long splints, imperfect below, are as long as the middle metacarpal and metatarsal bones; and, attached to the extremity of each, is a digit with three joints of the same general character as those of the middle digit, only very much smaller. These small digits are so disposed that they could have had but very little functional importance, and they must have been rather of the nature of the dew-claws, such as are to be found in many ruminant animals. The Hipparion, as the extinct European three-toed horse is called, in fact presents a foot similar to that of the American Protohippus except that in Hipparion the smaller digits are situated further back, and are of smaller proportional size than in the Protohippus.
"The ulna is slightly more distinct than in the horse; and the whole length of it, as a very slender shaft, intimately united with the radius, is completely traceable. The fibula appears to be in the same condition as in the horse. The teeth of the Hipparion are essentially similar to those of the horse, but the pattern of the grinders is in some respects a little more complex, and there is a depression on the face of the skull in front of the orbit, which is not seen in existing horses.
"In the earlier Miocene and perhaps in the Eocene deposits of some parts of Europe, another distinct animal has been discovered, which Cuvier, who first described some fragments of it, considered to be a Palæotherium, but as further discoveries threw new light on its structure, it was recognised as a distinct genus, under the name of Anchitherium.
"In its general characters the skeleton of Anchitherium is very similar to that of the horse, in fact Lartet and De Blainville called it Palæotherium equinum or Hippoides; and De Cristol, in 1847, said that it differed from Hipparion in little more than the characters of the teeth, and gave it the name of Hipparitherium. Each foot possesses three complete toes: while the lateral toes are much larger in proportion to the middle toe than in Hipparion, and doubtless rested on the ground in ordinary locomotion. The ulna is complete and quite distinct from the radius, although firmly united with the latter. The fibula seems also to have been complete; its lower end, though intimately united with that of the tibia, is clearly united with that of the latter bone. There are forty-four teeth; the incisors have no strong pit. The canines seem to have been well developed in both sexes. The first of the seven grinders, which, as I have said, is frequently absent, and, when it does exist, is small in the horse, is a good-sized and permanent tooth, while the grinder which follows it is but little larger than the hinder ones. The crowns of the grinders are short, and, although the fundamental pattern of the horse-tooth is discernible, the front and back ridges are less curved, the accessory pillars are wanting, and the valleys, much shallower, are not filled up with cement."
Then, after describing his early efforts to trace the descent of the horse from European fossils, Huxley goes on to relate the new light thrown on the matter from the American discoveries of Professor Marsh:
"You are all aware that, when your country was first discovered by Europeans, there were no traces of the existence of the horse in any part of the American continent. The accounts of the conquest of Mexico dwell on the astonishment of the natives of that country when they first became acquainted with that astounding phenomenon, a man seated upon a horse. Nevertheless, the investigations of American geologists have proved that the remains of horses occur in the most superficial deposits of both North and South America, just as they do in Europe. Therefore, for some reason or other,—no feasible suggestion on that subject, so far as I know, has been made,—the horse must have died out on this continent at some period preceding the discovery of America. Of late years there has been discovered in your Western territories that marvellous accumulation of deposits, admirably adapted for the preservation of organic remains, to which I referred the other evening, and which furnishes us with a consecutive series of records of the fauna of the older half of the Tertiary epoch, for which we have no parallel in Europe. The researches of Leidy and others have shewn that forms allied to the Hipparion and the Anchitherium are to be found among these remains. Rut it is only recently that the admirably conceived and most thoroughly and patiently worked-out investigations of Professor Marsh have given us a just idea of the vast fossil wealth and of the scientific importance of these deposits. I have had the advantage of glancing over the collections in Yale Museum; and I can truly say that, so far as my knowledge extends, there is no collection from any one region and series of strata comparable, for extent, or for care with which the remains have been got together, or for their scientific importance, to the series of fossils which he has deposited there. This vast collection has yielded evidence bearing on the question of the pedigree of the horse of the most striking character. It tends to show that we must look to America rather than to Europe for the original seat of the equine series; and that the archaic forms and successive modifications of the horse's ancestry are far better preserved here than in Europe.
"Professor Marsh's kindness has enabled me to put before you a diagram, every figure of which is an actual representation of some specimen which is to be seen at Yale at this present time.
"The succession of forms which he has brought together carries us from the top to the bottom of the Tertiaries. Firstly, there is the true horse. Next we have the American Pliocene form of the horse (Pliohippus): in the conformation of its limbs it presents some very slight deviations from the ordinary horse, and the crowns of the grinding teeth are shorter. Then comes the Protohippus, which represents the European Hipparion, having one large digit and two small ones on each foot, and the general characters of the forearm and leg to which I have referred. But it is more valuable than the European Hipparion for the reason that it is devoid of some of the peculiarities of that form—peculiarities which tend to show that the European Hipparion is rather a member of a collateral branch than a form in the direct line of succession. Next, in the backward order in time, is the Miohippus, which corresponds pretty nearly with the Anchitherium of Europe. It presents three complete toes—one large median and two smaller lateral ones: and there is a rudiment of that digit which answers to the little finger of the human race.
"The European pedigree of the horse stops here; in the America Tertiaries, on the contrary, the series of ancestral equine forms is continued into the Eocene formations. An older Miocene form, called Mesohippus, has three toes in front, with a large splint-like rudiment representing the little finger; and three toes behind. The radius and ulna, the tibia and fibula, are distinct, and the short crowned molar teeth are Anchitherioid in pattern.
"But the most important discovery of all is the Orohippus which comes from the Eocene formation, and is the oldest member of the equine series yet known. Here we find four complete toes on the front limb, three toes on the hind limb, a well-developed ulna, a well-developed fibula, and short-crowned grinders of a simple pattern.
"Thus, thanks to these important researches, it has become evident that, so far as our present knowledge extends, the history of the horse type is exactly and precisely that which could have been predicted from a knowledge of the principles of evolution; and the knowledge we now possess justifies us completely in the anticipation that, when the still lower Eocene deposits, and those which belong to the Cretaceous period have yielded up their remains of ancestral equine animals, we shall find, first, a form with four complete toes and a rudiment of the innermost or first digit in front, with probably a rudiment of the fifth digit in the hind foot; while, in the older forms, the series of digits will be more and more complete until we come to the five-toed animals, in which, if the doctrine of evolution is well founded, the whole series must have taken its origin."
Just as Huxley was successful, when only the ancestry to Miocene times was known, in predicting the discovery of older forms in the older Miocene and upper Eocene, so his prediction of older Eocene forms carrying the chain back to five-toed creatures proved correct. One of the new links was indeed discovered before his lecture had passed through the press, and he was able to add in a footnote some details of the structure of the four-toed Eohippus from the lower Eocene beds. Further discoveries have connected these with the five-toed ancestors of the Tapirs, and there is the strongest reason to suppose that we now know as nearly as possible the line of ancestry of the horse back to the primitive forms common to all the higher mammals. It would, of course, be beyond possibility of proof that the exact fossils described were the actual ancestors of the horse; but that they are exceedingly close allies of these, and that among them some actual ancestors exist cannot reasonably be doubted.
Although he had embarked upon geological work with some distaste, Huxley became very closely associated with it as years went on, and indeed, about the seventies, had abandoned his intention to devote himself specially to physiology, and declared himself to be in the first place a palæontologist. In 1876 he had accomplished so much that the Geological Society gave him its chief distinction, awarding him the Wollaston Medal in recognition of his services to geological science. He acted as Secretary to the Geological Society from 1859 to 1862, and he was President from 1868 to 1870. In 1862, the President being incapacitated, Huxley delivered as Deputy-President the Presidential Address. This address is famous in the history of geology, because for the first time it stated clearly and in permanent form a doctrine now taken as a first principle in all geological text-books. A large part of geology is the attempt to read the past history of the earth from the evidence given by the successive strata of rocks that form its crust.
"It is mathematically certain that, in any given vertical linear section of an undisturbed series of sedimentary deposits, the bed which lies lowest is the oldest. In many other vertical linear sections of the same series, of course corresponding beds will occur in a similar order."
It is of the utmost importance to determine whether or no the same series occurring vertically in the same order in different parts of the earth were deposited at the same time. To explain the problem, Huxley took the following concrete example:
"The Lias of England and the Lias of Germany, the Cretaceous rocks of Britain and the Cretaceous rocks of Southern India, are termed by geologists 'Contemporaneous' formations; but whenever any thoughtful geologist is asked whether he means to say that they were deposited at the same time, he says, 'No, only within the same great epoch.' And if, in pursuing the enquiry, he is asked what may be the approximate value in time of a 'great epoch'—whether it means a hundred years, or a thousand, or a million, or ten million years—his reply is, 'I cannot tell.'"
Most of the standard writers on palæontology had assumed that the presence in two beds at different parts of the world of the same fossils implied that the beds were contemporaneous, that they had been formed at the same time. Huxley pointed out that the fact of identical fossils being present was, on the whole, evidence against the beds having been formed at the same time. Even some of the older writers who believed in species having been created at definite places at definite times had seen that time must have been required for sets of animals to wander from the places in which they had come into existence. The newer theory of evolution was equally opposed to the notion of the appearance of similar animals at the same time on far-distant parts of the earth. For such reasons he proposed to reject the use of the word Contemporaneous as applied to rockbeds in different localities which contained the same fossils, and to replace it by the word Homotaxial, which meant no more than that the beds occupied corresponding places in the geological history of the earth. Huxley did not pretend that these arguments were entirely original: they represented the drift of the best geological opinion, and he seized hold of them and set them down as permanent geological truths.
In 1869, in a Presidential Address to the Geological Society, Huxley took up one of the burning questions of the day. In the early part of the century, the discoveries of geologists had been the occasion of great distress to those good people who clung to a literal interpretation of everything in the Bible. Long before the doctrine of evolution and the descent of man from lower animals had taken practical shape, there had been a battle royal between geologists who declared that the earth was many million years old, and had been inhabited at least by animals and plants for enormous periods, and those who clung to the traditional chronology which placed the date of creation only a few thousand years from now. The continued progress of geology, and the sturdy championship of it by men like Sedgwick, Chalmers, and Buckland, who were at the same time reputable theologians and distinguished men of science, had decided the battle in favour of the conclusions of science, and it was accepted generally that the earth was almost indefinitely old. At the same time, another and more strictly scientific dispute had been in progress. The older school of geologists, looking on the face of the world, and seeing it scarred by mighty fissures, displaying huge distortions of the beds in the crust, had argued that geological change had taken place by a series of mighty catastrophes. The tremendous results which they saw seemed to them only possible on the theory that unusual and gigantic displays of force had caused them. On the other hand, Hutton and Lyell attempted to find adequate explanation of the greatest changes in the slow forces which may be seen in operation at the present time. Slow movements of upheaval and depression, amounting at most to an inch or two in a century, may be shown to be actually in existence now, and such slow changes acting for very many centuries would account for the raising of continents above the sea, so that old sea-bottoms became the surface of the land, and for the depression of land areas so that new sedimentary rocks might be deposited upon them. They shewed how air and water slowly crumbled away the hardest rocks, and how rivers deepened their beds steadily but excessively slowly; and they held that while great catastrophic changes might occasionally have occurred, there was ample evidence of the present operation of forces which, granted sufficient time for their operation, would have made the crust of the earth such as it is. This doctrine of Uniformitarianism, of the action of similar forces in the past and present history of the earth, had almost completely triumphed over the older catastrophic views. As Huxley put it, the school of catastrophe put no limit to the violence of forces which had operated; the uniformitarians put no limit to the length of time during which forces had operated.
"Catastrophism has insisted upon the existence of a practically unlimited bank of force, on which the theorist might draw; and it has cherished the idea of development of the earth from a state in which its form, and the forces which it exerted, were very different from those which we now know.
"Uniformitarianism, on the other hand, has with equal justice insisted upon a practically unlimited bank of time, ready to discount any quantity of hypothetical paper. It has kept before our eyes the power of the infinitely little, time being granted, and has compelled us to exhaust known causes before flying to the unknown."
But there was a third influence at work in geology, an influence which may best be described in Huxley's own words:
"I shall not make what I have to say on this head clear unless I diverge, or seem to diverge, for a while, from the direct path of my discourse so far as to explain what I take to be the scope of geology itself. I conceive geology to be the history of the earth, in precisely the same sense as biology is the history of living beings; and I trust you will not think that I am overpowered by the influence of a dominant pursuit if I say that I trace a close analogy between these two histories.
"If I study a living being, under what heads does the knowledge I obtain fall? I can learn its structure, or what we call its Anatomy; and its development, or the series of changes it passes through to acquire its complete structure. Then I find that the living being has certain powers resulting from its own activities, and the interaction of these with the activities of other things—the knowledge of which is Physiology. Beyond this, the living being has a position in space and time, which is its Distribution. All these form the body of ascertainable facts which constitute the status quo of the living creature. But these facts have their causes; and the ascertainment of these causes is the doctrine of Ætiology.
"If we consider what is knowable about the earth, we shall find that such earth-knowledge—if I may so translate the word geology—falls into the same categories.
"What is termed stratigraphical geology is neither more nor less than the anatomy of the earth; and the history of the succession of the formations is a history of the succession of such anatomies, or corresponds with development, as distinct from generation.
"The internal heat of the earth, the elevation and depression of its crust, its belching forth of vapours, ashes, and lava, are its activities, in as strict a sense as are warmth and the movements and products of respiration the activities of an animal. The phenomena of the seasons, of the trade-winds, of the Gulf Stream, are as much the results of the reaction between these inner activities and outward forces, as are the budding of the leaves in spring, and their falling in autumn the effects of the interaction between the organisation of a plant and the solar light and heat. And, as the study of the activities of the living being is called its physiology, so are these phenomena the subject matter of an analogous telluric physiology, to which we sometimes give the name of meteorology; sometimes of physical geography, sometimes that of geology. Again, the earth has a place in space and time, and relations to other bodies in both these respects, which constitute its distribution. This subject is usually left to the astronomer; but a knowledge of its broad outlines seems to me to be an essential constituent of the stock of geological ideas.