250 THE CROSSING, &C, 



proportion of their respective characters, has been thus 

 most outraged, it is, to them, one should look, for the 

 greatest evil effects from interbreeding individuals, simi- 

 lar in the defects of their development. 



Each one of the varieties, respectively, of the 

 Pigeon, and of the Fowl, lacks all of the positive char- 

 acters which form the distinguishing marks of the 

 other varieties of the same species. As, therefore, the 

 absence, in any variety, or individual, of any character 

 of its species, must, ex hypothesi, be deleterious to its 

 physiological integrity, there is little room for marvel 

 at the evil results of the close-interbreeding of these 

 animals. 



There is as little occasion, to wonder at the good 

 which, Darwin alleges, results from crossing two varie- 

 ties of any one of these species. For, as he elsewhere 

 says, they "differ in an extreme degree, in some one 

 part, when compared with one another" (p. 16, Origin 

 of Species). When two such varieties are crossed, the 

 offspring acquires some character, or characters, which 

 either of its parents lacked, and so much the nearer is 

 the approximation, in the offspring, to the original, per- 

 fect type ; hence, the good resulting. 



These two species, the Pigeon, and the Fowl, are 

 the species, upon the divergence of character in whose 

 varieties, Darwin mainly relies, to show that varieties 

 are "incipient species," or distinct species, in the pro- 

 cess of formation. Yet, in the very exposition of his 

 hypothesis of such divergence, he reveals a state of 

 facts, which signally confutes such a view. For, he 

 clearly shows, by his remarks (which are frequently 



