200 



NATURE 



[November 6, igig 



of the alimentary canal, were not identical with 

 my terms, which apply only to portions of 

 ectodermal origin. The doctrine that the 

 caelum throughout the animal kingdom is 

 actually or implicitly an out-growth or a series 

 of out-growths of the archenteron was maintained 

 by me in opposition to the views of Haeckel and 

 Gegenbaur and others, and was finally established 

 by the observations of Sedgwick on Peripatus. 

 It was further proved by me that the vascular 

 system was an organic unit entirely independent of 

 the coelom, and my conception of "phleboedesis " 

 made an end of the German misinterpretations of 

 the body-cavities of Arthropods and Molluscs. 

 The abundant cumulative study of embryo- 

 log}' during these years has led to most 

 important conceptions with regard to the relation- 

 ship of various animals — <:.g. the origin of verte- 

 brate limbs. Present conclusions are really based 

 on inquiries into embryological beginnings, and 

 the whole interpretation of morphology in its em- 

 bryological aspect is still in progress. 



The Cell. 



The study of the structure of the cell itself, 

 and of the processes of cell division, shortly 

 after 1869 made a very great advance. Chromo- 

 somes and their importance, and the whole subject 

 of mitosis, became a part of our fundamental 

 knowledge. This very naturally, in view of the 

 importance of heredity with regard to the whole 

 theory of organic evolution, led to the minute 

 study of the structural facts connected with the 

 egg- and sperm-cells, as well as fertilisation and 

 the earliest divisions of the fertilised egg-cell to 

 form the embryo. This study, beginning about 

 the commencement of the period under considera- 

 tion, is still actively proceeding. Whilst it seems 

 that in the chromosome we have got very much 

 closer to an understanding of the actual visible 

 features relating to the phenomena of heredity, 

 yet there are important facts in course of dis- 

 covery. 



Oceanic Research. 



Another line which also suddenly came into 

 activity and has been a prominent feature since 

 1869 is deep-sea exploration, which began with 

 the voyage of the Challenger. When the first 

 number of Nature was published, this was having 

 its initiation under Dr. W. B. Carpenter and 

 Prof. Wyville Thompson, who, led by the dis- 

 coveries made by those who laid the first deep- 

 sea cables, had conceived the notion of explor- 

 ing great depths of the ocean by means of the 

 dredge. They obtained the brief loan of a war- 

 ship from the Government for the purpose of 

 their explorations. This led to the three years' 

 voyage of the specially fitted ship Challenger and 

 its staff of scientific experts, and the publication 

 afterwards of a magnificent series of reports. 

 This example of the Challenger has been followed 

 by every country, and valuable explorations of the 

 ocean — oceanographical research as it is called^ — 

 has become an established branch of scientific 

 inquiry. 



NO. 2610, VOL. 104] 



A complement of the pursuit of oceanography 

 by means of ships and apparatus for deep-sea 

 dredging has been the establishment of zoological 

 laboratories in specially suitable localities on the 

 seashore. The one organised on an international 

 basis by Dr. Anton Dohrn was the first to become 

 widely known and useful, although the French 

 naturalists had some years before this founded 

 marine laboratories — Coste at Concarneau and 

 Lacaze-Duthiers at Roscoff. Now they are estab- 

 lished everywhere. 



Palaeontology . 



Beginning with our starting point, and more 

 especially connected with the founders of the 

 Darwinian theory, there has been an immensely 

 important and productive activity in palaeonto- 

 logy. A large part of Huxley's scientific work 

 consists of the thirty or more valuable memoirs 

 on the remains of extinct fishes and reptiles 

 published by him as naturalist of the Geological 

 Survey. By his palaeontological studies he was 

 led to views as to the genealogical history and 

 connection of the birds and reptiles, and also as 

 to the special development of certain mammalian 

 forms, such as the horse. Also at this period 

 there developed in America an enormous activity 

 in palaeontological discovery. Up to 1869 we 

 knew some few of the extinct animals of America 

 through the work of Leidy. Marsh and Cope 

 then burst upon the scene with most astonishing 

 and valuable accounts of extinct dinosaurs, birds, 

 and mammals. These have been followed ever 

 since by a stream of important discoveries in 

 which Henry Fairfield Osborn is now the leader. 

 The stimulus of this work for the Darwinian 

 theory and its vast importance in relation to that 

 theory are obvious. 



Pathology. 



A study which has greatly developed, and 

 has had an effect on Darwinism and been re- 

 acted upon in turn by Darwinism, is that of 

 the whole field of pathology. Before i86g thej 

 germ theory and the importance of bacteria in • 

 disease had begun through Pasteur's work 

 to be appreciated. Since then knowledge 

 has accumulated, and the work of Lister has 

 fundamentally altered views as to the effective 

 nature of asepsis in the treatment of wounds. J 

 The outcome of this is an immensely increased 

 study and knowledge of bacteria and other para- 

 sitic organisms, and also of the means of resist- 

 ance to their attack. 



Special importance attaches to the recog- 

 nition by Metchnikoff of the function of 

 the colourless corpuscles as scavengers in the 

 blood and tissues — his doctrine of phagocytosis 

 and the rSle of phagocytes in immunity. Perhaps 

 most strikingly significant is his explanation of 

 inflammation, which is now seen in the light of 

 the Darwinian theory to be a life-preserving pro- 

 perty of the higher organisms in which, by local 

 arrest or slackening of the circulation, the access 



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