654 ZOOLOGY SECT. 



principle of serial homology ; by Peter Camper, who investigated 

 the pneumaticity of the bones of Birds, and was the first to apply 

 exact methods of measurement to the human skull ; by Alexander 

 Monro, who greatly advanced our knowledge of the anatomy 

 of fishes ; and by Poll, whose Testacea utriusque Sicilice is the 

 most famous of the older works on Mollusca. And in the domain 

 of out-door zoology the study of the actual life of animals with 

 but little regard to their structure or classification, or to the broader 

 scientific questions connected with them special mention must 

 be made of Gilbert White, whose Natural History and Antiquities 

 of Selborne is a classic both in science and letters. 



The latter part of the eighteenth century is also specially re- 

 markable for the publication of the earliest scientific speculations 

 on the origin of species. The idea of evolution is to be found in 

 the works of more than one of the great Greek and Roman philo- 

 sophers, such as Empedocles (495-415 B.C.) and Lucretius 

 (99-55 B.C.) ; and the writings of some of the Fathers of the 

 Church, such as Augustine (A.D. 353-430) and Thomas Aquinas 

 (1225-1274), seem to show that they had no objection to " deriva- 

 tive creation," or evolution under direct Divine superintendence. 

 But by about the middle of the sixteenth century the idea of 

 the immutability of specially created species had hardened into a 

 dogma which it was unsafe to question ; and, this state of things 

 continuing, the earliest of the great evolutionists, Buff on, felt 

 himself obliged to qualify all his speculations with a declaration, 

 sincere or ironical, of his belief that species were immutable. 

 Linnaeus, reckoning all higher groups as subjective, contended for 

 the real existence of species, saying " we recognise as many species 

 as were originally created," and this opinion was held by the vast 

 majority of naturalists, not only of his own time, but up to within 

 forty or fifty years of the present day. 



Buffon, born in the same year (1707) as Linnaeus, was, in his 

 methods and ideas, the exact opposite of his great systematising 

 contemporary. He wrote charming accounts of the external 

 characters and habits of animals, but declined to classify them, 

 on the ground that all arrangements of the kind were arbitrary, 

 and that it was easier, more useful, and more agreeable to consider 

 the lower animals in relation to ourselves. On this principle, 

 he begins his Histoire naturelle with Man, then takes up the various 

 domestic Mammals, and afterwards proceeds to consider the less 

 familiar forms. But he was essentially a philosophical zoologist ; 

 besides enunciating a theory of heredity, he grasped the idea of 

 homology, endeavoured to explain the facts of geographical 

 distribution, and, in a tentative and guarded way, admitted the 

 mutability of species, and advanced a hypothesis of their origin. 

 His speculations refer mainly to the modification, or, as he calls 

 it, degeneration, of domestic animals, and he sums up his position 



