148 BLASTOGENIC VARIATIONS. 



black, tabby, and tortoise-shell, and though they breed 

 promiscuously, very seldom throw intermediate colours. 

 Again, Sir R. Heron crossed during many years white, 

 black, brown, and fawn-coloured rabbits, and never once 

 got these colours mingled in the same animal, but often 

 got all four colours in the same litter.* All the off- 

 spring of dissimilarly coloured parents may therefore 

 resemble either parent, or some resemble one and 

 others the other, possibly quite apart from any ques- 

 tion of prepotency. 



Of undoubted cases of prepotency, but few have been 

 recorded with much detail or exactness. Of those col- 

 lected by Darwin, the most striking is that of a famous 

 black grayhound,t which " invariably got all his pup- 

 pies black, no matter what was the colour of the bitch " ; 

 but this dog " had a preponderance of black in his blood 

 both on the sire and dam side," a point which will be 

 referred to again later. Again, the famous bull Fav- 

 ourite is believed to have had a prepotent influence on 

 the shorthorn race. The male Manx cat appears to be 

 prepotent in transmitting his tailless condition. Pro- 

 fessor EwartJ has recorded a few additional cases of 

 prepotency. Thus a well-known breeder of highly bred 

 ponies used to boast that he had a filly so prepotent 

 through inbreeding that, though she were sent to the 

 best Clydesdale stallion in Scotland, she would throw a 

 colt showing no cart-horse blood, provided always that 

 the Clydesdale was not also the product of inbreeding. 

 Again, Professor Ewart points out that Jews, as a race, 



* " Animals and Plants," ii, p. 70. 



\L. c., ii. p. 40. 



\ " Penycuik Experiments," p. xli. 



