liESULTS OF A MENDELIAN EXPERIMENT ON FOWLS. 173 



12. Results o£ a Mendelian Experiment on Fowls, includ- 

 ing the Production of a Pile Breed. Bj J. T. 

 Cunningham, M.A., F.Z.S. 



[Received April 29, 1919 : Head May 27, 1919.] 

 (Plate I.*) 



In the ' Proceedings' of this Society for 1912 there was pub- 

 lished a paper by me under the title " Mendelian Experiments 

 on Fowls," in which I recorded certain results of a cross between 

 a male black-red Gallus banhiva and a Silky hen. The object of 

 the present paper is to describe the later generations obtained 

 from this cross, and especially to def-cribe in detail how it 

 produced a " pile " type of colour which bred true. In my 

 former paper I mentioned the fact that the two white cocks 

 of the first brood of the F„ generation at the age of 4.4 months 

 showed a yellowish-orange band of colour across the loins, and 

 the second of tliem had also some very pale patches on the neck 

 ventrally and above the eye on each side. In April 1916 I 

 exhibited at a meeting of the Zoological Society a number of 

 skins of the fowls bred from this cross, including specimens 

 of the pile birds of both sexes, but hitherto I have not recorded 

 in detail the characters observed in successive generations of the 

 crossed birds, as I propose to do in the present paper. 



All the generations were descended from a single ]3air of the 

 F^ generation, hatched from the original crossed pair at the 

 Zoological Gardens. To distinguish the generations, broods, 

 and individuals I have adopted the following formulae: the 

 number indicating the generation is placed below the line after 

 the letter F, it is followed by a Roman numeral indicating wdiich 

 of the successive broods of that generation the bird belongs to, 

 then follows an Arabic numeral indicating the particular bird 

 of the brood, and lastly the symbol of sex. Thus FY 1 $ is a 

 hen numbered 1 in the 5th hiood of the 4th genei'ation. 



In my former paper, which dealt only with the F^ generation, 

 I pointed out that the only two whites of the first brood showed 

 a trace of colour, whereas the oi-iginal silky of the crossed pair 

 liad no colour. Both these whites were cocks, and F, I 1 c? 

 showed a band of faint orange-yellow colour across the loins, 

 while F^I 2 cJ showed a similar l)and, still fainter, together with 

 some very pale patches on the neck ventrally and over each eye. 

 This condition was noted on September 30, the Ijii-ds having 

 been hatched on May 15 (age 4| nionths). 



There were two others, both wliite, in a second brood, date of 

 hatching not recorded. Of these F, II 2 cj' also showed a tinge 

 of yellowish colour across the loins. F^ II 1 5 was given away 

 at an early age, and no pigment on this hen was noted, although, 

 considering tliat at the time I was not aware of the sexual 

 * For explanation of the Piute see p. 203. 



