210 Leri-featherwq in Poultry 



The second point of interest appears in all three of the matings. 

 There is a marked tendency throughout for the ^^ to be more heavil}' 

 feathered than the ? %. More than half the /t/" are found in the 

 highest of the three grades, while the majority of the $ % occur in the 

 lowest one. In his experiments on leg-feathering (" booting ") Davenport 

 ('09) grades his results but he does not appear to have noticed any 

 connection between the degree of leg-feathering and sex. Since the 

 sex of the offspring is not recorded in his tables it is not possible to 

 test this point by his data. It is however one that may well be borne 

 in mind by any future investigator of this character. 



Several observers have published data on the inheritance of feathered 

 leg in poultr}-. Of these the results recorded by Davenport are the 

 most extensive and at the same time the most instructive. Many of 

 his crosses, e.specially those in which birds of the F^ and later gene- 

 rations were used (cf Table 3S, pp. 52, 58) arc too involved for analysis, 

 but for the Cochin and Dark Brahma crosses (Table :-i4, pp. 48, 49) 

 the data are more favourable, and consideration of them has led me to 

 the conclusion that a simpler interpretation can be found for them 

 than that which Davenport has suggested. If we suppose that in these 

 feathered-legged races two factors A and B may be present, either of 

 which determines leg-feathering, the different proportions of clean- 

 legged birds in the various F.^ matings recorded by Davenport may 

 very well occur. In demonstration of this I have constructed Table IV 

 on p. 211 from the data given on pp. 48 and 49 of Davenport's paper. 

 The assumption is made that the original parents on the feathered-leg 

 side all transmitted the factor A to the F^ otfsi)ring subsequently tested. 

 In many instances they also transmitted factor B while in others this 

 factor was not passed on. It is assumed that the clean-legged breeds 

 used, whether white Leghorn or Minorca, lacked both of these two 

 factors. The restatement of Davenport's results set out on p. 211 clearly 

 supports the view I have just advocated as to the factors which give 

 rise to the feathered leg. The actual numbei's are in fair accordance 

 with expectation throughout and in many cases the two sets of figures 

 are practically identical. It is probable therefore that in Cochins and 

 Brahmas two factors are concerned in leg feathering, and not one on\y as 

 in Langshans. This tallies with the grade of leg-feathering found in 

 the two former breeds, in which the feathers are more numerous and 

 more highly developed than in the last named. 



Cochins were also used by Hurst who found that the F^ birds pro- 



