662 ZOOLOGY SECT. 



sense a systematist with a sufficient knowledge of anatomy, 

 thoroughly conversant with the breeding of domestic animals and 

 cultivated plants, a keen observer of external nature, both organic 

 and inorganic, and with unrivalled experience as a traveller. It 

 is not surprising, therefore, that the wealth of illustration, the close 

 reasoning, and the philosophic spirit of the Origin converted the 

 whole scientific world to the general doctrine of transformism 

 within twenty years. The theory of Natural Selection, the Survival 

 of the Fittest, or the Preservation of Favoured Races in the Struggle 

 for Life, was first grasped by Darwin in 1838, but was not published 

 until 1858, when it was announced simultaneously by himself and 

 by Alfred Russel Wallace. Both these authors had, however, 

 been anticipated by W. C. Wells in 1813, and by Patrick Matthew 

 in 1831. Darwin's other works, especially The Variations of 

 Animals and Plants under Domestication and The Descent of Man, 

 rank among the most important contributions to philosophical 

 Biology. With them must be mentioned the luminous Principles 

 of Biology of Herbert Spencer, who consistently upheld the direct 

 action of the environment as a factor in evolution. Wallace, on 

 the other hand, is a pure selectionist, while Darwin held " that 

 natural selection has been the main but not the exclusive means of 

 modification." 



The additions to zoological knowledge made by the voyagers 

 of the eighteenth century have been referred to ; even more 

 important are the numerous great scientific expeditions of the 

 nineteenth and twentieth centuries. Among the most prominent 

 of these are the voyages of the French ships Astrolabe, Uranie, 

 Bonite and Geographe, in which researches were carried on by 

 Peron and La Sueur, Quoy and Gaimard, Eydoux and 

 Souleyet, and Hombron and Jacquinot, and given to the 

 world in splendidly illustrated folios. Still more famous is the 

 voyage of H.M.S. Beagle (1831-36), in which Darwin gained his 

 extraordinarily wide and accurate knowledge of natural history, 

 and the narration of which is published in his Naturalist's 

 Voyage. Other celebrated voyages are those of H.M.S. Rattle- 

 snake (1846-50), of which T. H. Huxley was assistant-surgeon ; 

 of H.M.SS. Erebus and Terror, accompanied by Sir J. D. Hooker ; 

 of the American " Wilkes " expedition, with J. D. Dana as 

 naturalist, and of the Austrian frigate Novara. But the most 

 famous and complete of all scientific voyages was that of H.M.S. 

 Challenger, in 1872-76, the five years' cruise of which was 

 marked by discoveries of great importance by the scientific staff, 

 Sir Wyville Thomson, John Murray, H. N. Moseley, 

 and Willemoes-Suhm, while the zoological material collected 

 on ths voyage was worked out by the leading zoologists in all 

 parts of the world, and the results published in thirty handsome 

 and fully-illustrated quarto volumes. 



