34: PRINCIPLES OF STOCK-BREEDING. 



the defect in the system of the ancestors is apparently 

 transmitted directly to the offspring, where it makes 

 its appearance in the congenital form or as a predis- 

 position. 



Animals that are, however, free from constitu- 

 tional taint, may transmit indirectly to their offspring 

 a predisposition to certain forms of disease, through a 

 faulty conformation or proportion of the organization, 

 that can hardly be considered abnormal. 



Animals inheriting such peculiarities of structure 

 may remain healthy under favorable conditions ; but 

 they are liable to disease, from the effects of exposure 

 or hard work, that would not be injurious to those 

 with a better-proportioned organization. 



According to Finlay Dun, a disproportion in the 

 width and strength of the leg below the hock to the 

 width and strength above the hock, predisposes to 

 spavin ; a straight hock and a short os calcis, inclin- 

 ing forward, gives a tendency to curbs ; " round legs 

 and small knees, to which the tendons are tightly 

 bound, are especially subject to strains ; " while a pre- 

 disposition to navicular disease is found "in horses 

 with narrow chests, upright pasterns, and out-turned 

 toes." 1 



"Many farm -horses, as well as others without 

 much breeding, are remarkable for consuming large 

 quantities of food, for soft and flabby muscular sys- 

 tems, and for round limbs containing an unusual pro- 

 portion of cellular tissue. These characters are no- 

 toriously hereditary, of which indubitable evidence is 

 afforded by their existence in many different indi- 



1 Journal of the Royal Agricultural Society, vol. xiv., p. 115. 



