SINGLE- COMB WHITE LEGHORN AND HOUDAN. 21 



PREVIOUS INVESTIGATIONS. 



During the progress of ray experiments appeared the second report to 

 the Evolution Committee of the Royal Society by Bateson and others. 

 This contains a paper by Hurst (1905, p. 133) giving his results with White 

 Leghorn male X Houdan female. These will be considered in comparison 

 with my results. 



MATERIAL. 



The mothers were two Houdan hens* (fig. 16) purchased from a dealer 

 as pure stock. They agreed well with the standard requirements. When 

 bred with a Houdan male they produced only typical Houdans. 



The father was a Single-comb White Leghorn f likewise of unknown 

 ancestry. The plumage of No. I3A is devoid of black pigment, and mated 

 with White Leghorn hens it has produced only White Leghorn offspring. 



RESULTS. 



i. GENERAL PLUMAGE COLOR. First hybrid generation. Of 41 individuals 

 all were white in plumage (fig. 17), but almost without exception both in 

 down plumage and that of the adult there were traces of black on one or 

 more feathers, particularly those of the back ; more especially was this true 

 of the females than of the males. 



Hurst (1905, p. 133) got ii black chicks out of 105 offspring and in the 

 first plumage these developed into 6 black (all pullets) and 5 barred (all 

 cockerels). Here also females have more pigment than males. Of the white 

 chicks all except two developed black ticking. Doubtless these two were 

 males. 



Second hybrid generation. When these hybrids were crossed inter se, out of 

 50 individuals 9 were markedly pigmented like the Houdan. This is 18 per 

 cent of all cases, expectation being 25 per cent. With larger numbers 

 Hurst (1905, p. 138) got 24.3 per cent black. Equally striking is the 

 occurrence of many pure white individuals along with the impure whites. 

 The pure whites that were reared to maturity proved to be males ; the impure 

 whites were females. 



First hybrid (No. 8j $ ) crossed with white Leghorn {No. // 9 ). The father 

 was pure white ; the mother was speckled with black. Of 22 offspring all were 

 white, but some had single pigmented feathers. All males (9) are pure white, 

 excepting No. 562, which has some black on two feathers of the left wing 

 coverts, and No. 649, which has one-half of one right wing covert black. 

 My only certain female has a score of partly black feathers. Hurst (1905, 

 p. 139) obtained 66 clear white chicks and 69 white, ticked with black. I 



*Nos. 8 and n, received July i, 1904, from Geo. C. Ely. 

 f No. I3A., received Sept. 15, 1904, from a farmer. 



