172 L. J. COLE AND W. A. LIPPINCOTT. 



accordingly." His explanation of the natural difference in shade 

 in the two sexes is that the males are homozygous whereas the 

 females are heterozygous with respect to barring. 'The males, 

 therefore, have twice as much tendency to barring as do the 

 females. The males are therefore more barred than the females 

 and hence are lighter in color." By "more barred" Spillman 

 means that the white bars are wider in proportion to the black. 

 This difference in the relative widths of the white and black 

 bands on the feathers may be noted in the normal cockerel and 

 pullet, Figs. 2 and 3, but is more evident in the individual feathers 

 shown in Figs. 7-10. These feathers, while not from the same 

 individuals shown in Figs. 2 and 3, are from birds of the same 

 breeding as these and "Kansas 1050." Fig. 7 is a neck feather 

 from hen 804, which was a flock sister of "Kansas 1050," while 

 Fig. 8 is a feather from the cushion, or lower back, of the same 

 bird. Fig. 9 represents a hackle feather, as it is called in the 

 male, from the neck of a cock bird, IO4E, which is the son of a 

 flock sister of "Kansas 1050." Fig. 10 is a saddle feather from 

 the same male, being from the position corresponding to the 

 cushion in the hen. It will be noticed that in addition to the dif- 

 ferences in shape in the two sexes, the white and black bars on 

 the hen's feathers are of practically the same width, while on 

 those of the cock the white bars average considerably wider. 



From the photograph of the neck feathers of "Kansas 1050" 

 in Fig. 4 the impression is gained that the masculine feathers of 

 the right side have broader white bars; but that such is not the 

 case on the lower back is evident from a careful inspection of 

 Fig. 5. Furthermore, the fact that the white bars are of the 

 same width in the old and new feathers of both these regions is 

 convincingly shown in Figs. 11-14. Figs, n and 12 are neck 

 and lower back feathers respectively from the left or "feminine" 

 side, while Figs. 13 and 14 are corresponding feathers from the 

 right or "masculine" side. The lighter appearance of the 

 "cock" feathers of the right side is therefore not due in this case 

 to relatively wider white bars, but must be attributed to the 

 fact that they are older and consequently the black has faded to 

 some extent, and to the difference in form and structure. Normal 

 cock feathers are more elongate in these regions, and they differ 



