16 A NEW THEORY OF EVOLUTION. 



breeder finds himself in the presence of un- 

 expected obstacles to further development, 

 and they prove insurmountable. If the 

 young stock go unmated to the age when 

 cattle not highly bred reach puberty, the 

 animals, whether male or female, will prob- 

 ably prove infertile, and that without any 

 obvious cause. 



The breeder also finds that development 

 has so stimulated precocity that cases have 

 been known where a female only eleven 

 months old has produced a calf; and such 

 cases at thirteen months are not uncommon. 



The dam of eleven months had conceived 

 when a calf only two months old, instead of 

 at fifteen to eighteen months the usual age 

 of puberty among animals not highly bred. 



In these circumstances the breeder seeks 

 to avoid sterility in the mature animals by 

 breeding from his young stock when barely 

 half grown. But as the immature dam can- 



o 



not be fully protected in the struggle between 

 her own growth and that of her unborn 

 calf, both suffer, and both fail to equal their 

 progenitors in development. Practically, a 

 full expression of the type has been reached, 

 and, to maintain the existence of the herd, 

 its standard of excellence must be lowered 

 by immature mating. 



