Thoughts on Species. 375 



allowed ; and that a closer and a closer aflSnity might give a lon- 

 ger and a longer range of fertility. But the case just now allud- 

 ed to seems to cut the hypothesis short ; and moreover it is not 

 reasonable to attribute such indefiniteness to nature's outlines, for 

 it is at variance with the spirit of her system. 



Were such a case demonstrated by well established facts, it 

 would necessarily be admitted ; and I would add, that investiga- 

 tions directed to this point are the most important that modern 

 science can undertake. But until proved by arguments better 

 than those drawn from domesticated animals, we may plead the 

 general principle against the possibilities on the other side. If 

 there is a law to be discovered, it is a wide and comprehensive 

 law, for such are all nature's principles. Nature will teach it 

 not in one corner of her system only, but more or less in every 

 part. We have therefore a right to ask for well defined facts, 

 taken from the study of successive generations of the interbreed- 

 ing of species known to be distinct. 



Least of all should we expect that a law, which is so rigid 

 among plants and the lower animals, should have its main ex- 

 ceptions in the highest class of the animal kingdom, and its most 

 extravagant violations in the genus Homo ; for if there are more 

 than one species of Man, they have become in the main indefi- 

 nite by intermixture. The very crown of the kingdom has been 

 despoiled ; for a kingdom in nature is perfect only as it retains 

 all its original parts in their full symetry, uudefaced and un- 

 blurred. Man, by receiving a plastic body, in accordance with 

 a law that species most capable of domestication should necessa- 

 rily be most pliant, was fitted to take the whole earth as his do- 

 minion, and live under every zone. And surely it would have 

 been a very clumsy method of accomplishing the same result, 

 to have made him of many species, all admitting of indefinite 

 or nearly indefinite hibridization,. in direct opposition to a grand 

 principle elsewhere recognized in the organic kingdoms. It 

 would have been using a process that produces impotence or 

 nothing among animals for the perpetuation and progress of the 

 human race. 



There are other ways of accounting for the limited produc- 

 tiveness of the mulatto, without appealing to a distinction o* 

 species. There are causes, independent of mixture, which are 

 making the Indian to melt away before the white man, the Sand- 

 wich Islander and all savage people to sink into the ground be- 



