POLYGAMOUS FACTORS 81 



Are they further members of the series with bay, black, 

 and chestnut ? The question is really two questions, 

 namely, How do grey and dun stand to each other and 

 to the others as regards dominance and recessiveness ? 

 and. Are they also the result of single factors ? 



Fourteen bay sires 



got . . . 616 (2) (2) 163 (6) — 68 — (4) 



Eighteen bay sires 



got . . . 366 57 (3) 51 41 (1) 35 9 (1) 



Thirty-six bay sires 



got . . . 1296 92 134 167 83 19 103 (16) 88 



Four black sires got. 13 12 — (1) 19 — (3) 11 — 

 Twelve black sires 



got . . . 266 75 37 (3) 53 8 (1) 7 17 



Because of their paucity in modern breeds, both 

 colours are very short in data, and reliance has to be 

 placed upon early Thoroughbred and similar records 

 supplemented by more recent but scantier information 

 collected from more modern but smaller breeds and 

 among unregistered stock. 



There is also the further difficulty that grey data 

 must be handled with unusual care because no grey 

 horse is born grey, and greys are frequently registered 

 as of some other colour while the original misdescription 

 is not always corrected later. White foals, which may 

 be albinos, are occasionally born, but the foal which is 

 to become grey is usually dull black or of some dark 



F 



