74 TEE POPULAR SCIENCE MONTELX. 



this we know, the fact exists, and we find its general explanation in 

 the conditions of existence, in the conditions of the environment. 



Now, man, who has progressed upon the earth a much longer time 

 than the turkey or the rabbit, who has been upon the globe for thou- 

 sands of years, living under the most diverse, the most opposite con- 

 ditions, multiplying further the causes of modification by his manners, 

 his habits, his kind of life, by the more or less care he takes of himself 

 man, I say, is certainly found in conditions of variation much more 

 marked than those which have been encountered by the animals we 

 have cited. It is not, then, surprising that men, from one group to an- 

 other, present differences of which we here see the specimens. If there 

 is any thing in them to astonish us, it is that these differences are not 

 more considerable. 



In your turn you ask of the polygenesists for this is the name 

 given to the philosophers who believe in the multiplicity of the human 

 species how is it that when the white man comes to any country what- 

 ever, at the antipodes, in America, in Polynesia how is it, I say, that 

 everywhere he crosses with human groups that differ most completely 

 from him ; that these unions are always fertile, and that everywhere 

 he has left traces of his passage in producing a mixed population ? 



If you press your interlocutor a little, he will quite often deny the 

 reality of species ; he will thus put himself in contradiction with all 

 naturalists without exception, botanists or zoologists with all the 

 eminent minds who, following Buffon, Tournefort, Jussieu, Cuvier, 

 Geoffroy Saint-Hilaire, have studied vegetables and animals, outside of 

 all discussion, and without thought of man. 



In thus dealing with the question, the polygenesist falls into disa- 

 greement with the best-established science. 



Sometimes, also, you will hear him declare that man is an excep- 

 tion, that he has his particular laws, that the arguments taken from 

 plants and animals are not applicable to him. Answer him, then, in 

 the name of physiology, in the name of all the natural sciences, that he 

 is certainly mistaken. 



It is quite as impossible that an organized and living body should 

 escape the laws of organization and life as that material substances 

 should escape the laws that govern inorganic matter. Therefore, 

 man, an organized and living being, obeys, as such, all general laws, 

 and those of crossing like the rest. The conclusion we have drawn is 

 then legitimate, and the nature of the arguments employed to combat 

 it is a further proof in its favor. 



Gentlemen, the subject of this lecture, which has occupied about an 

 hour, at the Museum took up an entire course. The exposition has 

 necessarily been brief. But I hope you have seen reasons strong 

 enough to make you accept my view. 



If doubts remain, try to come to my lectures. Some of you will be 

 able, perhaps. I sometimes see working-men on the seats of my lee- 



