On the Unity of the Human Species. 21 



knowledge, truth has at hist triumphed. New lights have re- 

 cently been shed on the question of the origin of the human 

 species ; and it is these new facts that we are about to ex- 

 plain to those who seek the truth in sincerity. 



The identity of the human species has been attempted to 

 be demonstrated by two different methods. The first, which 

 was partially pointed out by BufFon, consists in directing at- 

 tention to the circumstance, that species very different from 

 each other avoid sexual connection, while those that are very 

 nearly allied produce steril mules by crossing. The diverse 

 races of one and the same species can alone have offspring 

 capable of as indefinite reproduction as their parents. In 

 other words, species remote from each other can neither repro- 

 duce nor perpetuate themselves ; nearly allied species may be 

 productive, but they cannot perpetuate their race ; the most 

 diverse races both reproduce and perpetuate themselves. 



If we apply these facts to the varieties of the human 

 species, we are led to the conclusion that they form only 

 one true species ; for the most dissimilar races of men 

 give birth, by crossing, to individuals who transmit their 

 own qualities to their descendants. The European colonies 

 in America present all possible examples of crossing in 

 different degrees, the effects of which render this conclusion 

 obvious. 



By the second method, that of Blumenbach, we arrive at 

 the same results. On a great number of animals, whether 

 wild or domestic, we may produce very considerable varia- 

 tions under the influence of external agents. These are, in 

 many cases, much greater than those which distinguish the 

 most dissimilar human races. 



The observations of modern naturalists have thrown a flood 

 of light on these questions, by shewing the influence which 

 climate, and a return to a free state, exercise on the races of 

 animals, — first subjected to the empire of man in Europe, 

 then exported to ximerica, and allowed to run wild in the 

 vast savannahs of the New World. In this point of view, 

 the labours of M. Roulin possess a high degree of importance, 

 and ought to be classed in the first rank. 



In order to explain the variations which man has under- 



