TEE ORIGIN OF SPECIES. 25 



proof of independent origination is attainable from 

 the nature of the case, the overthrow of particular 

 schemes of derivation has not established the opposite 

 proposition. The futility of each hypothesis thus far 

 proposed to account for derivation may be made 

 apparent, or unanswerable objections may be urged 

 against it ; and each victory of the kind may render 

 derivation more improbable, and therefore specific 

 creation more probable, without settling the question 

 either way. New facts, or new arguments and a new 

 mode of viewing the question, may some day change 

 the whole aspect of the case. It is with the latter 

 that Mr. Darwin now reopens the discussion. 



Having conceived the idea that varieties are in- 

 cipient species, he is led to study variation in the field 

 where it shows itself most strikingly, and affords the 

 greatest facilities to investigation. Thoughtful natu- 

 ralists have had increasing grounds to suspect that 

 a reexamination of the question of species in zoology 

 and botany, commencing with those races which man 

 knows most about, viz., the domesticated and culti- 

 vated races, would be likely somewhat to modify the 

 received idea of the entire fixity of species. This 

 field, rich with various but unsystematized stores of 

 knowledge accumulated by cultivators and breeders, 

 has been generally neglected by naturalists, because 

 these races are not in a state of nature ; whereas they 

 deserve particular attention on this very account, as 

 experiments, or the materials for experiments, ready 

 to our hand. In domestication we vary some of the 

 natural conditions of a species, and thus learn experi- 

 mentally what changes are within the reach of vary 



