HEREDITY OF RACEHORSE STAMINA 73 



Here the numbers are few, in all only one 

 hundred and seventy-three matings. This, however, 

 is unavoidable, for it is difficult to find a sprin- 

 ter with even ten winning produce. Missel Thrush 

 probably should be included in the above clas- 

 sification, for his percentage of intermediate and 

 stayers is small. He is the first foal of the 

 St. Leger winner. Throstle, who so far has been 

 somewhat of a stud failure ; but as Missel Thrush 

 never "ran, and as his brother Songcraft, by Orme, 

 and his half-brother Grey Bird, by Grey Leg, could 

 stay a mile, he may be given the benefit of the doubt 

 till his further stud record proves his composition. 

 The sprinter Sundridge has been omitted from the 

 list, first because he might have stayed a mile or over, 

 had he been sound in his wind ; then, in the second 

 place, his winning produce of three-year-olds and 

 upwards, as yet, only total fourteen, viz. : Seven 

 sprinters, six intermediates, and one stayer — that 

 is if the Derby winner Sunstar really is a stayer. In 

 any event, Sunstar's dam, Doris, is an interesting 

 example of the staying factor being sex limited. 

 Doris, like many other good brood mares, was just a 

 five furlong sprinter, but it seems clear that some of 

 her gametes carry R. 



Reverting to Table XL, the offspring table of the 

 ten sprinting sires, I would emphasize that the result 

 in the first mating of PP sires with PP mares, 

 allowing for sex limitation of the R factor in some of 

 the mares, is pretty much what one would expect ; 

 for, in place of getting the whole eighty offspring as 



