HEREDITY OF RACEHORSE STAMINA 65 



plays a part — though in the thoroughbred only a 

 minor one — in relation to the rapidity with which 

 muscles tire during work, and allowing for other 

 disturbing factors, the twenty-eight exceptions are 

 not beyond reasonable expectation. A more exact 

 knowledge of the individual horses would probably 

 reduce these twenty- eight exceptions to a negligible 

 quantity. 



The objection may be urged that the winning male 

 stock of a stallion are a selected sample, and that the 

 incidence of non-stayers will be heavier in those of his 

 produce which never run on the flat. This is true in 

 the case of non-staying sires, but the argument has 

 little or no weight in regard to RR stallions. Slow 

 their colts may be, and not infrequently are, but it 

 is rare in the absence of disturbing conditions, such 

 as roaring or blood vessel breaking, to find one which 

 cannot stay five furlongs. 



The Mating of Sires and Dams both of 

 Known Performances. 



So far, we have only considered the results of 

 mating the seventeen sires of known staying capacity, 

 shown in Table TIL, with a random sample of mares 

 whose performances were not considered. But now 

 it is necessary to study the results of mating sires of 

 known performances with dams also of known per- 

 formances. 



As already stated, no great reliance can be placed 

 on public form, as regards stamina, prior to 1899. 

 The greater part of these dams were in training prior 



E 



