36 A TREATISE ON HORSE-BREEDING. 



or of a pair of individuals distinguished for the 

 same peculiarity, to transmit it to the offspring 

 should excite no surprise in the mind of the 

 breeder. Let it be remembered always that 

 heredity transmits with certainty, only what has 

 become a fixed characteristic in the race. Sports, 

 accidental variations and individual peculiari- 

 ties only occur in opposition to this law, and 

 their transmission is at best uncertain. Hered- 

 ity may be depended on to govern the general 

 characteristics which determine the species and 

 the less general ones which distinguish the 

 breed, but when we come to individual charac- 

 teristics, which have never acquired a general 

 character in the ancestry, it frequently fails. 

 In short, the transmission of the greater share of 

 all the characteristics is a thing of universal occur- 

 rence, but their transmission in toto is an ideal 

 conception that is never realized; and only in pro- 

 portion as the ancestry has assumed a fixed and 

 unvarying type do we find this ideal of the 

 effect of heredity approximated. 



That peculiarity called atavism, or reversion, 

 so often noticed in our domesticated animals, 

 and which has so frequently set at naught the 

 calculations of the breeder, has often been 

 quoted as an illustration of the failure of the 

 law of heredity; but it is in fact only a tribute 

 to its power. By selection, change of climate 

 or of nutrition, or by crossing, or by all of these 



