60 THE MENDEL JOURNAL 



It is at once apparent that Tiger Lily, Clonavarn, 

 Novitiate, and Ornament are not of the same composi- 

 tion as Lucy Ashton, although all were sprinters. Out 

 of fourteen matings Lucy Ashton did not breed a 

 stayer of either sex, though mated nine times with 

 horses of PR and five times with horses of RR composi- 

 tion ; therefore it is clear that she was a mare of 

 gametic composition PP. The other four mares all 

 bred stayers, and, manifestly, were of gametic com- 

 position PR ; but since they were sprinters, the R 

 was inhibited in their soma by the sex limiting 

 character, and we may therefore symbolise them as 

 PRI. Lucy Ashton may also have carried I, but 

 there is no evidence to show that this was the case. 

 We cannot conclude, therefore, that she transmitted 

 it to her son Wolfs Crag. But it is permissible to 

 surmise that the stallions Martagon, Count Schom- 

 berg, Marco, and Collar all derived this inhibiting 

 factor from their dams, carried it as a recessive, and, 

 in due course, passed it on to certain of their daugh- 

 ters, in which it was again manifested. 



Sex limitation at once explains the paradox that 

 many of our best racehorses and most noted stayers 

 have been out of mares which were almost useless on 

 a racecourse after two years of age, principally, if not 

 solely, owing to lack of stamina. Some were abso- 

 lutely useless. Here are a few examples which may 

 be of interest. They are by no means exhaustive. 

 If space permitted numerous additions could be 

 made. See Table VII. 



