Z2.4 THE HISTORY OF BIOLOGY 



the seas' wide distribution BufTon cites the discovery of fossilized marine 

 animals, especially shells, up in the mountains, and even the stratified 

 nature of the geological formation in general. ^ In the essay "Epoques de la 

 nature" BufFon divides the history of the earth into seven periods: (i) when 

 the earth and the planets were formed, (x) when the great mountain-ranges 

 were created, (3) when water covered the mainland, (4) when the water 

 subsided and the volcanoes began their activity, (5) when elephants and 

 other tropical animals inhabited the North, (6) when the continents were 

 separated from one another, (7) when man appeared. It would take too 

 long to give a more detailed account of his description of these periods. In 

 this geological theory he makes Vulcanism in general play a more important 

 part than in the earlier work, and the tide becomes of less significance. The 

 greatest service he rendered, however, is that he clearly realized the change 

 in the animal and vegetable kingdoms from epoch to epoch; he tried to work 

 out a "natural history of creation," based on law-bound evolution; he specu- 

 lates upon the origin of the various life-forms and the place of their appear- 

 ance and combines these two circumstances with calculations as to climatic 

 changes and other purely physical conditions — in all this a pioneer of the 

 conception of nature which was not generally accepted until a century after 

 his time. 



His biological theory 

 BuFFON has expounded his biological theories in a volume bearing the title 

 Historic naturelle des animaux. It begins with an investigation into the differ- 

 ence between animals, vegetables, and minerals and establishes the fact that 

 there is no absolutely definite boundary between the animal and the vegetable 

 kingdoms, but that transition forms may exist; common to both kingdoms 

 is the individuals' power of giving rise by means of reproduction to new 

 individuals like themselves. Another common property is the power of 

 growth; this shows that a fundamental agreement prevails amongst all liv- 

 ing creatures, in spite of differences in detail, whereas only matter as a 

 fundamental substance is common to animate and inanimate things. Both 

 animals and vegetables arise as species, the criterion of which is that they 

 propagate; on the other hand, there is no question of a common creative 

 origin. On the whole BufFon refuses to see in the origin of life the result of a 



^ As an example of the lengths to which it was still possible to go during the " ' enlightened 

 eighteenth century in explanation of natural phenomena, it may be mentioned that Voltaire, 

 who, however, would pass as a disciple of Newton's, declared that Buffon's theory of the origin 

 of fossils up in the mountains was irrational; the shells that had been found there had probably 

 been left there by pilgrims who took them from the East. The two geniuses consequently came 

 into serious disagreement; but later they were reconciled and Voltaire declared BufFon to be 

 a second Archimedes. Buffon capped this compliment with the assurance that no one would 

 ever be called Voltaire the Second. Voltaire's flattery shows, however, that BufFon was con- 

 sidered, and indeed wished to be considered, primarily a physicist. 



