CROSSING AND CLOSE-INTERBREEDING. 207 



close-interbreeding, and ascribes them to "a great law 

 of nature," — a mode of explanation which obviously 

 is naught but a rendering of his ignorance into the 

 semblance of knowledge. He remarks (p. 327, Origin 

 of Species) : 



" How ignorant we are, on the precise causes of 

 sterility;" and, he says (on p. 109, Origin of Species), 

 "that close interbreeding is a general law of nature, 

 utterly ignorant though we be of the meaning of the 

 law." 



Thus he states his "great law of nature" (p. 109, 

 Origin of Species) : 



" I have collected so large a body of facts, showing, 

 in accordance with the universal testimony of breeders, 

 that, with animals and plants, a cross between different 

 varieties, or between individuals of the same variety, 

 but of another strain, gives vigor and fertility to the 

 offspring; and, on the other hand, that close-inter- 

 breeding diminishes vigor and fertility; that these 

 facts alone incline me to believe that it is a general 

 law of nature {utterly ignorant though we be of the 

 meaning of the law) that no organic being fertilizes 

 itself for an eternity of generations ; but that a cross 

 with another individual is occasionally ,^-perhaps, at 

 very long intervals, — indispensable." 



If it be "a general law of nature," that evil should 

 flow from close-interbreeding, and that good should 

 result from crossing, why do not the same degree 

 of evil, and the same degree of good, result, respec- 

 tively, from crossing, and from close-interbreeding, in 

 different individuals, when there is a like degree of 

 relationship, or a like distinction between the animals 

 or plants coupled ? We should at least, expect a like 



