SEVENTEENTH AND EIGHTEENTH CENTURIES 2.Z7 

 analyse the growth of speech in the child, and the influence of mental emo- 

 tions upon facial expression; he discusses the power of mental perceptions to 

 reproduce reality and insists on science's dependence upon them. He investi- 

 gates the circumstances of death at various ages; he gives statistics showing 

 the mortality in certain French provinces and seeks with the aid of "proba- 

 bility calculations" to ascertain the longevity of various ages; he compiles 

 data with regard to the peculiarities of wild tribes and abnormal phenomena 

 in civilized peoples. Above all, he maintains that man has his bodily func- 

 tions in common with the animals, but that, on the other hand, there is a 

 fundamental psychical difference between them, which renders it impossible 

 to compare human and animal intellectual qualities. 



His Xoogra-phy 

 Of the animals Buffon, as already mentioned, had time to complete only the 

 quadrupeds and birds, which are dealt with in detailed monographs covering 

 each species. Naturally, these are each of varying value; all of them however 

 share in common a brilliant exposition and a universal treatment of the sub- 

 ject, in striking contrast both to the earlier zoographers' motley mass of 

 notes and to Linnasus's brief, summary diagnoses. As a describer of nature 

 Buffon is of fundamental importance, in certain respects still unexcelled. It 

 would take too long to enter into the peculiarities of his zoography; it need 

 only be pointed out that it is not merely formal services that have earned it 

 its well-merited fame, but in many of his descriptions, particularly in those 

 of birds, there are a number of keen and striking detailed observations as to 

 mode of life, reproduction, and other biologically interesting factors. 



Daubenton s cofnparative anatomy 

 To each monograph on mammalian animals Buffon 's collaborator, Dauben- 

 ton, has added an account of the animal's anatomy. By way of introduction 

 he sets forth the principles on which to base this kind of general — nowa- 

 days we should say "comparative" — anatomy, in contrast to the descrip- 

 tive, which had hitherto been practised. He considers that all animals should 

 be investigated in respect of their most vital organs — bone-structure, heart, 

 brain, respiratory, digestive, excretive, and sexual organs — and the results 

 thus obtained compared. Following this principle, an account is given of 

 every mammal's anatomy, particularly the bone-structure: the bone-struc- 

 ture of the horse is compared in detail with that of man, and the bones of 

 other animal species are mutually compared. Such a comparative examination 

 of the anatomy of various animals carried out on a uniform plan was at that 

 period something new and proved of great significance for the future; the 

 part played by comparative anatomy in modern biology is too well known to 

 need any special emphasis here. 



Thus Buffon carried out his plan of presenting nature, both inanimate 

 and animate, as one whole, evolved and held together by purely mechanical 



