1S2 TUB DIBCINT OF MAN. 



CHAPTER VII. 



ON THE RACES OF MAN. 



The nature and value of specific characters— Application to the races 

 of man— Arguments in favor of, and opposed to, ranking the so- 

 called races of man as distinct species— Sub-species— Monogenlsts 

 and polygenists— Convergence of character— Numerous points of 

 resemblance in body and mind between the most distinct races of 

 man — The state of man when he first spread over the earth — Each 

 race not descended froni a single pair — The extinction of races — 

 The formation of races — The effects of crossing— Slight influence 

 of the direct action of the conditions of life — Slight or no influence 

 of natural selection— Sexual selection. 



It is not my intention here to describe tlie several so-called 

 races of men; but I am about to inquire wliat is the value of the 

 differences between them under a classiflcatory point of view, 

 and how they have originated. In determining whether two or 

 more allied forms ought to be ranked as species or varieties, 

 naturalists are practically guided by the following considera- 

 tions; namely, the amount of difference between them, and 

 whether such differences relate to few or many points of struc- 

 ture, and whether they are of physiological importance; but 

 more especially whether they are constant. Constancy of char- 

 acter is what is chiefly valued and sought for by naturalists. 

 Whenever it can be shown, or rendered probable, that the forms 

 in question have remained distinct for a long period, this be- 

 comes an argument of much weight in favor of treating them as 

 species. Even a slight degree of sterility between any two forms 

 when first crossed, or in their offspring, is generally considered 

 as a decisive test of their specific distinctness; and their con- 

 tinued persistence without blending within the same area, is 

 usually accepted as sufficient evidence, either of some degree of 

 mutual sterility, or in the case of animals of some mutual repug- 

 nance to pairing. 



Independently of fusion from intercrossing, the complete ab- 

 sence, in a well-investigated region, of varieties linking togeth-r 

 any two closely-allied forms, is probably the most important of 

 all the criterions of their specific distinctness; and this is a some- 



