THE ORIGIN OF SPECIES 175 



it tax all his intelligence to separate any variety which arises, 

 and to breed selectively from it, the destructive agencies 

 incessantly at work in Nature, if they find one variety to be 

 more soluble in circumstances than the other, will inevitably, 

 in the long run, eliminate it. 



A frequent and a just objection to the Lamarckian hypo- 

 thesis of the transmutation of species is based upon the 

 absence of transitional forms between many species. But 

 against the Darwinian hypothesis this argument has no 

 force. Indeed, one of the most valuable and suggestive 

 parts of Mr. Darwin's work is that in which he proves, 

 that the frequent absence of transitions is a necessary con- 

 sequence of his doctrine, and that the stock whence two or 

 more species have sprung, need in no respect be intermediate 

 between these species. If any two species have arisen from 

 a common stock in the same way as the carrier and the 

 pouter, say, have arisen from the rock-pigeon, then the com- 

 mon stock of these two species need be no more intermediate 

 between the two than the rock-pigeon is between the carrier 

 and pouter. Clearly appreciate the force of this analogy, 

 and all the arguments against the origin of species by selec- 

 tion, based on the absence of transitional forms, fall to the 

 ground. And Mr. Darwin's position might, we think, have 

 been even stronger than it is if he had not embarrassed him- 

 self with the aphorism, " Natura non facit saltum," which 

 turns up so often in his pages. We believe, as we have said 

 above, that Nature does make jumps now and then, and a 

 recognition of the fact is of no small importance in disposing 

 of many minor objections to the doctrine of transmutation. 



But we must pause. The discussion of Mr. Darwin's 

 arguments in detail would lead us far beyond the limits 

 within which we proposed, at starting, to confine this article. 

 Our object has been attained if we have given an intelligible, 

 however brief, account of the established facts connected 

 with species, and of the relation of the explanation of those 

 facts offered by Mr. Darwin to the theoretical views held by 

 his predecessors and his contemporaries, and, above all, to the 

 requirements of scientific logic. We have ventured to point 

 out that it does not, as yet, satisfy all those requirements ; 

 but we do not hesitate to assert that it is as superior to any 

 preceding or contemporary hypothesis, in the extent of 

 observational and experimental basis on which it rests, in 

 its rigorously scientific method, and in its power of explaining 

 biological phenomena, as was the hypothesis of Copernicus 



