PREPOTENCY. 59 



the French ewes and the resulting cross-bred 

 ewes. The two breeds gradually yielded up 

 their character, but one much more readily 

 and rapidly than the other, showing a marked 

 difference in the native vigor of the two breeds. 

 But it is surely not necessary to multiply 

 examples. What has already been said is 

 certainly ample to found those applications to 

 practice on, which will presently be made, and 

 to convince every one that to secure the best 

 results in breeding cattle for market, bulls 

 must be used from breeds of marked prepo- 

 tency; and that in breeding cattle of pure breeds 

 there is a wide difference in the value of indi- 

 viduals; and that for the highest results bulls 

 of the greatest prepotency are to be sought. 

 That is all that could be hoped for. So great a 

 master as Darwin recognizes the difficulties in 

 anything more than an experimental recog- 

 nition of prepotency, and says: "On the whole 

 the subject of prepotency is extremely intri- 

 cate, from its varying so much in strength, even 

 in regard to the same character in different 

 animals, from its running either differently in 

 both sexes, or, as frequently is the case with 

 animals, * * * much stronger in the one 

 sex than the other, from the existence of sec- 

 ondary sexual characters from the transmis- 

 sion of certain characters being limited by sex 

 from certain characters not blending to- 



