&C, OP PIGEONS AND FOWLS. 211 



bly, has, to contribute to the offspring, a little of posi- 

 tive structure in which the other is deficient. 



The slight differences, which distinguish individuals 

 in the same herd, or flock, will, in some cases, where 

 such differences are positive, and where the degenera- 

 tion, reduction, or suppression of the several characters, 

 is not too far gone, suffice to avert the evils of inter- 

 breeding. They may avert them, for a time; or, make 

 the evils manifest themselves, only when there is the 

 closest interbreeding; or, after many generations of 

 such close-interbreeding. 



Darwin commends certain processes of selection by 

 man, which involve the loss, to individuals, of char- 

 acters of their species, and he also notes the evils of 

 lessened fertility, and of -lessened constitutional vigor, 

 which follow the loss or reduction of any characters ; 

 yet, with the two terms of an obvious relation, thus 

 clearly present to him, and while he even formulates 

 such relation, he is conveniently obtuse to the fact, 

 that it bears most conclusively against his theory. 

 Thus, in the quotations given below, he approvingly 

 quotes the reduction and the suppression of charac- 

 ters ; and then remarks the deterioration, attendant 

 upon such "serious defects in structure," and upon 

 such' violation of " the mutual relations of the parts." 

 Yet, notwithstanding all, he pursues the uneven tenor 

 of his hypothesis, — namely, that divergence of charac- 

 ter will produce distinct species, — seemingly serenely 

 oblivious of having mentioned anything which, in the 

 least, militated against his views. 



