THE CROSSING, &C, OF CATTLE, ET Ali. 333 



very distinct breed. The slight, positive differences of 

 a near variety, or of a different strain, will frequently 

 suffice to ward off "the evils of disproportion ; and by 

 this crossing with a different strain only, the special 

 excellence of the breed is saved from injury, or from 

 abatement, while sufficient vigor and fertility are ac- 

 quired. It is even possible, to bring up the individuals, 

 to the original, perfect type, by merely taking advan- 

 tage of the slight, positive differences which present 

 themselves at times in the individuals of the same 

 variety. As Darwin's facts show, breeders have learned, 

 that it is not necessary to cross the animals of a 

 variety, with a very distinct variety, in order to stave 

 off the evil of interbreeding. Breeders, however, are 

 just as likely as not, in crossing, to select those individ- 

 uals of a different strain or sub-variety, which have 

 negative differences distinguishing them, as they are 

 to cross their animals with the individuals of such dif- 

 ferent strain, which have positive peculiarities to con- 

 tribute to the offspring. Breeders, together with Dar- 

 win, fancy, that the good resulting from a cross, is due 

 to difference, per se ; whereas, it is solely positive, dif- 

 ferences, from which the favorable result accrues. 



29 



