4 MR. ADAIR UIGHTON ON 



dilution factor, it cannot be epistatic to the saturation factoi'. 

 In these circumstances it must be recessive, and being so, there 

 should be no blacks in the blue to blue matings. Very possibly 

 the blacks were dark blues verging on black, but, anyhow, the 

 blue to blue matings are too few to form a reliable guide. 



Turning next to the bi-indle and brindle matings. On the 

 hypothesis that brindle is recessive to black and blue and domi- 

 nant over red or fawn and white, there should be no blacks or 

 blues from brindle to brindle matings. Theoretically, with the 

 blackness stripped off, the brindles become dominant or, as 

 dominants are rare, impure dominant to the recessive red or 

 fawns and whites. Tims the mating is one of impure dominant 

 to impure dominant, and the expected result from 2829 whelps 

 would be 2121 brindle to 707 red or fawns and whites. The 

 actual result was 30 blacks and blues : 2118 brindles and 681 

 red or fawns and whites. 



The 30 blacks wei'e made up of 14 blacks ; 9 black and whites ; 

 6 blues and 1 blue and white. The error of deviation is so 

 small that I think it may be laid down to inaccurac}'- of 

 description. 



In the case of brindle to red or fawn, there were 2932 whelps, 

 and as it was a case of imj^m^e dominant to recessive the expec- 

 tation was that there Avould be equality or 1466 brindles to 

 1466 red or fawns and whites. The actual result was 1465 to» 

 1458, but there were, in addition, 9 blacks, which once again, 

 though unsatisfactory, must be attributed to descriptive error. 



The last of the more simple results are reached in the matings 

 between red oi' fawn and red or fawn. On the hypothesis that 

 red or fawn are hypostatic to everything but white, the expec- 

 tation is that there Avould be no colours in the 2925 whelps but 

 red or fawns and a few whites. Actually, the figures observed 

 were 10 blacks, blues and brindles: 2910 red or fawns and 



5 whites. The incidence of the epistatic colours black, blue, and 

 brindle is so low that one is justified in assuming that their 

 presence in this mating is due to personal error rather than to 

 genetics. 



Reviewing the above results, I think I have proved that 

 greyhound coat coloui'S follow the sequence of black, wdiich is 

 epistatic, blue, brindle, red or fawn, and v/hite, which is hypostatic, 

 and that, secondly, blue is a dilute black. 



From supplementary statistics I find that there are undoubtedly 

 pure dominants for both black and brindle, and, as I have shown, 

 red or fawns bi-eed true, which is invariably the case with a 

 recessive character. Thus it follows that if such were of any 

 practical use to the coursing man, he would have no difficulty in 

 establishing pure breediug strains of either black, brindle, red 

 or fawn. 



I now turn to the secondary results of the matings, and these 

 are somewhat more complicated than the primary data alread}^ 

 discussed. 



