42 HYBRIDS AND MONGRELS COMPARED. [Chap. IX. 



with another species, the hybrids do not differ mnch. 

 But this conclusion, as far as I can make out, is 

 founded on a single experiment; and seems directly 

 opposed to the results of several experiments made by 

 Kolreuter. 



Such alone are the unimportant differences which 

 Gartner is able to point out between hybrid and 

 mongrel plants. On the other hand, the degrees and 

 kinds of resemblance in mongrels and in hybrids to 

 their respective parents, more especially in hybrids 

 produced from nearly related species, follow according 

 to Gartner the same laws. When two species are 

 crossed, one has sometimes a prepotent power of 

 impressing its likeness on the hybrid. So I believe 

 it to be with varieties of plants ; and with animals one 

 variety certainly often has this prepotent power over 

 another variety. Hybrid plants produced from a 

 reciprocal cross, generally resemble each other closely ; 

 and so it is with mongrel plants from a reciprocal cross. 

 Both hybrids and mongrels can be reduced to either 

 pure parent-form, by repeated crosses in successive 

 generations with either parent. 



These several remarks are apparently applicable to 

 animals ; but the subject is here much complicated, 

 partly owing to the existence of secondary sexual 

 characters ; but more especially owing to prepotency in 

 transmitting likeness running more strongly in one sex 

 than in the other, both when one species is crossed with 

 another, and when one variety is crossed with another 

 variety. For instance, I think those authors are right 

 who maintain that the ass has a prepotent power over 

 the horse, so that both the mule and the hinny resemble 

 more closely the ass than the horse ; but that the pre- 



