76 A MANUAL OF MENDELISM 



Knowing as we do now that chestnut roans and 

 black roans are merely chestnuts and blacks carrying 

 the additional effect of another independent factor and 

 that greys are very liable to misdescription, we can infer 

 that chestnut is recessive to all other colours and that 

 black, by throwing both blacks and chestnuts but no 

 others, is a simple dominant to chestnut but recessive 

 to the others. 



The first of these inferences is of course confirmed 

 by the experience of the breeders of the Suffolk Punch, 

 while the second is confirmed by data* collected by 

 Dr. Walther in the records of the Trakehnen, Beberbeck, 

 and Halbturn studs and published in his " Beitrage zur 

 Kentniss der Vererbung der Pferdefarben " in 1912, 

 for, excluding 3 greys entries as erroneous, he found 

 that black with black gave 852 black foals and 74 

 chestnuts. 



The first inference was also confirmed by data col- 

 lected from the Thoroughbred Stud Book, that is, 

 Weatherby's " General Stud Book," by Mr. C. C. Hurst 

 and published in the " Proceedings of the Royal Society " 

 in 1906. But Mr. Hurst arrived at another conclusion 

 of new and equal importance, namely, that bay — ^that is 

 bay and brown taken together as one — is also dominant 

 to chestnut. His figures were : 



