136 THE 'ORIGIN OF SPECIES.' [1860. 



the single origin of man All the races of man are so 



infinitely closer together than to any ape, that (as in the case 

 of descent of all mammals from one progenitor), I should 

 look at all races of men as having certainly descended from 

 one parent. I should look at it as probable that the races of 

 men were less numerous and less divergent formerly than 

 now, unless, indeed, some lower and more aberrant race even 

 than the Hottentot has become extinct. Supposing, as I do 

 for one believe, that our dogs have descended from two or 

 three wolves, jackals, &c. ; yet these have, on our view, de- 

 scended from a single remote unknown progenitor. With 

 domestic dogs the question is simply whether the whole 

 amount of difference has been produced since man domesti- 

 cated a single species ; or whether part of the difference 

 arises in the state of nature. Agassiz and Co. think the 

 negro and Caucasian are now distinct species, and it is a 

 mere vain discussion whether, when they were rather less 

 distinct, they would, on this standard of specific value, de- 

 serve to be called species. 



I agree with your answer which you give to yourself on 

 this point ; and the simile of man now keeping down any new 

 man which might be developed, strikes me as good and new. 

 The white man is " improving off the face of the earth " even 

 races nearly his equals. With respect to islands, I think I 

 would trust to want of time alone, and not- to bats and Ro- 

 dents. 



N.B. I know of no rodents on oceanic islands (except 

 my Galapagos mouse, which may have been introduced by 

 man) keeping down the development of other classes. Still 

 much more weight I should attribute to there being now, 

 neither in islands nor elsewhere, [any] known animals of a 

 grade of organisation intermediate between mammals, fish, 

 reptiles, &c., whence a new mammal could be developed. If 

 every vertebrate were destroyed throughout the world, except 

 our now well-established reptiles, millions of ages might elapse 

 before reptiles could become highly developed on a scale 

 equal to mammals ; and, on the principle of inheritance, 



