222 LOWER ANIMALS. 



years of his life he became the progenitor of more horses of ex- 

 treme speed than any sire except Hambletonian. 



It is part of the history of the trotting horse during the nine- 

 teenth century that those stallions which were selected for their 

 fine qualities for breeding purposes and were kept without being 

 trained, never produced anything of value, while those stallions 

 which were not highly esteemed, but which were regularly trained, 

 became the progenitors of great speed in the second and third 

 generations. 



TRANSMISSION BY SEX IN HORSES. 



The records for trotting horses enable us to trace in them 

 the transmission by sex of acquired functional capacity. Fifty 

 years ago it was considered detrimental to the breeding value of 

 a stallion to use him for racing purposes. Those used in the stud 

 were not raced and those raced were not used in the stud. This 

 prejudice did not extend to mares, and the result was that the 

 most famous trotters were mares. During more recent years there 

 has been a change of sentiment in this regard, and stallions are 

 now both bred and raced. Under these conditions the extra age 

 of sires as compared to dams is beginning to tell, and stallions are 

 now slightly more speedy than mares. 



In examining the pedigrees of fast horses I found that the 

 sires of fast stallions were older than the sires of fast mares, and 

 that the dams of fast mares were older than the dams of fast 

 stallions. With some minor exceptions at fragmentary portions of 

 the pedigrees, this peculiarity is found to extend to> the grandsires 

 and granddams, and to the great-grandsires and great-granddams. 

 In other words, very fast stallions arise as the result of a fortuitous 

 combination of old sires, and very fast mares arise as the result of 

 a fortuitous combination of old dams. 



