September 19, 1895] 



NATURE 



495 



with his brilliant ability and unique personality, have founded a 

 great school of Marine Zoology. 



To return to the early fifties, Huxley — whose recent loss to 

 science, to philosophy, to culture, we, in common with the 

 civilised world, now deplore — at that time just returned from 

 the memorable voyage of the Kattlesiiakc, was opening out his 

 newly acquired treasures of comparative anatomy witli papers 

 on Siphonophora and on Sagitta, and one on the structure of 

 Ascidians, in which he urged — fourteen years before Kowalevsky 

 established it on embryological evidence in 1866 — that their re- 

 lations were with Amphioxus, as we now believe, rather than 

 with the Polyzoa or the Lamellibranchiata, as had formerly been 

 supposed. Bates was then on the Amazons, Wallace was just 

 going out to the .Malay Archipelago, Wyville Thomson, Hincks, 

 and Carpenter, the successors of Forbes, Johnston, and Alder, 

 were beginning their life-work. Abroad that great teacher and 

 investigator, Johannes Miiller, was training amongst his pupils 

 the most eminent zoologists, anatomists, and physiologists of the 

 succeeding cjuarter centur)-. In this country, as we have seen, 

 Huxley was just beginning to publish that splendid series (jf re- 

 searches into the structure of nearly all groups in the animal 

 kingdom, to which comparative anatomy owes so much. 



In fact, the few years before and after the last Ipswich meet- 

 ing witnessed the activity of some of the greatest of our British 

 zoologists — the time was pregnant with work which has .since 

 advanced, and in some respects revolutionised our subject. It 

 was then still usual for the naturalist to have a competent know- 

 ledge of the whole range of the natural sciences. Edward 

 Forbes, for example, was a botanist and a geologist, as well as a 

 zoologist. 1 le occupied the chair of Botany at King's College, 

 London, and the presidential chair of the Geological Section of 

 the British Association at Liverpool in 1S54. That excessive 

 specialisation, from which most of us suffer in the present day, 

 had not yet arisen ; and in the comprehensive, but perhaps not 

 very detailed, survey of his subject taken by one of the field 

 naturalists of that time, we find the beginnings of different lines 

 of work, which have since developed into some half-dozen dis- 

 tinct departments of zoology, are now often studied indepen- 

 dently, and are in some real danger of losing touch with one 

 another (see diagram). 



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MEDICAL 



The spendid anatomical and " morphological " researches of 

 Huxley and Joliannes .Muller have been continued by the more 

 minute histological or cellular work rendered possible by im- 

 provements of the microtome and the microscope, until at last 

 I in these latter years we investigate not merely the cellular 

 ■ anatomy of the \iO(\'j,hvA the anatomy of Ihc cell —\i miittiA we 

 I are permitted to talk of "cell" at all, and are not rather con- 

 Mi strained to express our results in terms of " cytomicrosomes," 

 " somacules," or " idiosomes,"and to regard our morphological 

 unit, the cell, as a symbiotic community containing two colonies 

 of totally dissimilar organisms (see Watas6 in " Wood's Holl 

 Biological Lectures," 1893). To such cytological investigations 

 may well be applied Lord Macaulay's aphorism, " .\ point 



NO. I35I, VOL. 52] 



which yesterday was invisible is its goal to-day, and will be its 



starting-point to-morrow." • 



Somewhat similar advances in methods have led us from the 

 life-histories studied of old to the new and fascinating science of 

 embryology. The elder Milne-Edwards and Van Benedenknew 

 that in their life-histories Ascidians produced tadpole-like young. 

 Kowalevsky (1S66) showed that in their embryonic stages these 

 Ascidian tadpoles have the beginnings of their chief systems of 

 organs formed in essentially the .same manner and from the 

 same embrj'onic layers as in the case of the frog's tadpole 

 or any other typical young vertebrate ; and now we are not 

 content with less than tracing what is called the "cell-lineage" 

 of such Ascidian embryos, so as to show the ancestry and de- 

 scendants, the traditions, peculiarities of, and inlluencesat work 

 upon each of the embryonic cells — or areas of [jrotoplasm — 

 throughout many complicated stages. And there is now open- 

 ing up from this a great new field of experimental and 

 "mechanical' embryologj-, in which we seek the clue to the 

 explanation of particular processes and changes by determining 

 under what conditions they take place, and how they are affected 

 by altered conditions. We are brought face to face with such 

 curious problems as. Why does a frog's egg, in the two-celled 

 stage, of which one-half has been destroyed, develop into 

 half an embryo when it is kept with one (the black) surface 

 uppermost, and into — not half an embryo, but— a whole embryo 

 of half the usual she if kept with the other (the white) surface 

 upwards. Apparently, according to the conditions of the ex- 

 periment, we may get half embryos or whole embryos of half 

 size from one of the first two cells of the frog's egg.' 



One of the most characteristic studies of the older field 

 naturalists, the observation of habits, has now become, under 

 the influence of Darwinism, the " Bionomics'" of the present 

 day, the study of the relations between habit and structure and 

 environment — a most fascinating and promising field of inves- 

 tigation, which may be confidently expected to tell us much in 

 the future in regard to the competition between species, and the 

 useful or indifferent nature of specific characters. 



Other distinct lines of zoological investigation, upon which I 

 shall not dwell, are geographical distribution and paUeontology 

 — subjects in which the zoologist comes into contact with, and 

 may be of some service to his fellow-workers in geolog>-. And 

 there still remains the central avenue of the wide zoological 

 domain — that of speciography and systematic zoology — which 

 has been cultivated by the great classifiers and monographers 

 from Linnaeus to H^eckel, and has culminated in our times in 

 the magnificent series of fifty quarto volumes, setting forth the 

 scientific results of the Challenger Expedition ; a voyage of 

 discovery comparable only in its important and wide-reaching 

 results with the voyages of Columbus, Gama and Magellan at 

 the end of the fifteenth century. It is now so long since the 

 Challenger investigations commencetl that few I suppose outside 

 the range of professional zoologists are aware that although the 

 expedition took place in 1872 to 1S76, the work resulting there- 

 from has been going on actively until now — for nearly a quarter 

 of a century in all — and in a sense, and a very real one, will 

 never cease, for the Challenger has left an indelible mark upon 

 science, and will remain through the ages exercising its powerful, 

 guiding influence, like the work of Aristotle, Newton, and 

 Darwin. 



Most of the authors of the special memoirs on the sea and its 

 various kinds of inhabitants, have interpreted in a liberal spirit 

 the instructions they received to examine and describe the collec- 

 tions entrusted to them, and have given us very valuable sum- 

 maries of the condition of our knowledge of the animals in 

 question, while some of the reports are little less than complete 

 monographs of the groups. I desire to ])ay a tribute of respect 

 to my former teacher and scientific chief. Sir Wyville Thomson, 

 to whose initiative, along with Dr. W. B. Carpenter, we owe 

 the first inception of our now celebrated deep-sea dredging ex- 

 peditions, and to whose scientific enthusiasm, combined with 

 administrative skill, is due in great part the successful accom- 

 plishment of the Lightning, the Porcupine, and the Challenger 

 Expeditions. Wyville Thomson lived long enough to super- 

 intend the first examination of the collections brought home, 

 their division into groups, and the allotment of these to special- 

 ists for description. He enlisted the services of his many scien- 

 tific friends at home and abroad, he arranged the general plan 

 of the work, decided upon the librm of publication, and died in 



' See Morg.in, ".An.lt. .Anzeig.," iSg^j^x. Bd. p. k-zx. ;mtl recent p.in'TS bv 

 Roux Hertwig, Born, and O. Schultze. 



