36 



extent than tlie share they have had in begetting them." 

 " Crossing a pure, well fixed breed with one whose characters 

 are less fixed and constant will bring the impure breed very 

 quickly to the standard of the pure, and this will be a change 

 for the better or the worse, according as this pure breed excels 

 or comes below the other in personal qualities. Thus breeding 

 our common cows with a poor aboriginal race of any country 

 will deteriorate them rapidly, while crossing them with Short- 

 Horn, Ayrshires, or Dutch, will with equal rapidity improve 

 them. Again, crossing of these improved breeds with a poor 

 but strongly fixed and prepotent breed will be at the risk of 

 obtaining a reversion to a more primitive and still poorer type 

 of the race. Crossing thus becomes an art, whose principles 

 must be studied and acted on in order to succeed." 



There are many well authenticated cases where the imagina- 

 tion of the mother seems to have left its impression on the 

 offspring. It is related, on authority of Col. Bryant, Fair- 

 haven, that a number of black cows, sent to an island, had by 

 accident a dun steer introduced among them, and that their 

 calves were without exception of a dun color. Other instances 

 of the same kind, especially among the lower animals, might 

 be mentioned. 



The effect of the first pregnancy on succeeding ones is a 

 principle supported on the authority of Agassiz and others, 

 and by many well known instances which confirm their state- 

 ments. I have noticed particularly in breeding dogs that the 

 first pregnancy has had a most noticeable influence on after 

 progeny. This should be a warning to careful breeders not to 

 allow their heifers to have connection with any but superior 

 bulls. 



Youali:, in speaking of disease, says there is scarcely a 

 malady to which the horse is subject which is not hereditary. 

 If this is true of the equine, it can hardly fail to apply in some 

 degree to the bovine^ species. Seeing that hereditary evil 

 qualities may be transmitted with almost as great facility as 

 good qualities, we cannot be too cautious in selecting for 

 breeding only animals of good health and vigor. 



