136 EVOLUTIONISTS OF THE EIGHTEENTH CENTURY. 



ment in the changes observed in the different races 

 of men as connected with differences of climate. 

 He carefully traces the modifications which are due 

 to the domestication of various wild animals. He 

 speaks of the formation of new varieties of animals 

 by artificial selection, and shows that similar results 

 may be produced in Nature by geographical migra- 

 tion, thus having in mind the ' segregation ' law, 

 later developed by Wagner. 



The struggle for existence, the elimination of the 

 least-perfected species, the contest between the 

 fecundity of certain species and their constant 

 destruction, are all clearly expressed in various pas- 

 sages. Thus we find Buffon anticipating Malthus l 

 in the following passage : 



" Le cours ordinaire de la nature vivante, est en gne"ral toujours 

 constant, toujours le meme ; son mouvement, toujoursj rgulier, 

 roule sur deux points inbranlables : 1'un, la fcondit sans bornes 

 donne"e a toutes les especes ; 1'autre, les obstacles sans nombre 

 qui rduisent cette fcondit a une mesure determinee et ne lais- 

 sent en tout temps qu'a peu pres la meme quantite d'individus de 

 chaque espece." 



Again, his idea of the elimination of the least- 

 perfected species is shown in the following passage, 

 also quoted by De Lanessan : 



" Les especes les moins parfaites, les plus dedicates, les plus 

 pesantes, les moins agissantes, les moins armies, etc., ont de"ja dis- 

 paru or disparaitront." 



1 Thomas Robert Malthus (1766-1834) published his famous work, An 

 Essay on the Principle of Population as it affects the Future Improvement of 

 Society, in 1798, while Buffon made the last addition to his Histoire Naturclle 

 in 1789. As another instance of continuity it is interesting to recall the obli- 

 gation Darwin expresses to Malthus. 



