COAT COLOUR IX GREYHOUKDS. 



111 the black to black ma tings, if the blacks are taken' as 

 impuie dominants and of two soi-ts : 



(1) blacks carrying a brindle factor as recessive, 



(2) blacks carrying a red or fawn factor as recessive, 



and the incidence of both blacks are equally numerous, the ratio 

 arising should be: — black, 12 : brindle, 3 : red or fawn, 1. 

 Further, if every black dog or bitch carried both brindle and led 

 or fawn factors, the incidence would be tlie same, as red or fawn 

 could only appear in the absence of brindle. 



It will be observed that the incidence of black came out cor- 

 rectly in the black to black and blue to blue matings, but in the 

 place of the brindies being in the ratio of three to one red or fawns, 

 the colours ai-e almost equally distributed in the black to black 

 matings, whereas in the blue to blue matings the red or fawns 

 are almost twice as numerous as the brindies. These results 

 cannot be explained by the law of probability, based on the inter- 

 action of factors arising out of the hypothesis, already proved, 

 that brindle is dominant over red or fawn. 



In the mating of black to brindle, the Mendelian expectation 

 is: — black, 4: brindle 3, red or fawn 1; and the 3053 whelps 

 should therefore give 1526 blacks : 1145 brindies and 381 red or 

 fawns and whites. The observed results gave 1533 blacks and 

 blues: 1018 brindies and 484 red or fawns and whites. 



Here the results are sufficiently close — having regard to the 

 fact that the actual incidence of the recessive factors in the 

 DR blacks is unknown — to be taken as in accordance with 

 probability. 



On the other hand, the Stud Book returns for black to red or 

 fawn show, as regards the incidence of brindies and red or fawn, 

 a totally unexpected result. In the 3039 Avhelps the expected 

 result was that there would be 1519 blacks: 789'5 brindies and 

 789*5 red or fawns ; whereas the actual result was 1525 blacks : 

 492 brindies, and 1007 red or fawn and whites. At the moment 

 the explanation of these figures is beyond me, but I think it is 

 worth noting that in the black to black matings the incidence of 

 brindies and red or fawns is practically equal, and the same holds 

 true in the black to blue matings. In the black to brindle and 

 the black to red or fawn matings there is again a similarity, as 

 in the former the ratio of brindle to red or fawn is as 2 to 1, 

 whilst in the latter the ratio is practically reversed. This may 

 be nothing moi-e than a coincidence of figures, but somehow I 

 think it holds the key to the explanation. My own idea was 

 that black carries a factor which produces either brindle or red 

 according as to the factor introduced by the other parent, but 

 if this were so, in the black to red or fawn matings there 

 should be no brindies, whereas there were actually 492 in 

 3039 whelps. 



In passing to the mixed colours, it is interebting to note that 



