RELATING TO SECONDARY SEXUAL CHARACTERS. 7 



not, therefore, call for special notice. All of the new feathers were in 

 shape, pattern, and general coloration strikingly different from the 

 original feathers, some of which were at first still present, the old 

 feathers of course showing no change. 



After completely molting, the appearance of the birds may be 

 gathered from the photographs (plate 5) and from the colored drawings 

 (plates 1 and 3). The male now has in all points the plumage of a 

 typical cock-feathered male bird of other breeds. This is startlingly 

 apparent in the hackle, back, rump, sickle, and tail-covert feathers. 

 Instead of the laced feathers that are characteristic of both male and 

 female, the whole upper surface of the bird appears reddish or yellowish, 

 the black marginal edging of the feathers having disappeared. A 

 detailed comparison of the feathers of the different regions will show 

 how great a change has taken place. (See page 8.) 



In plates 6 and 8 the feathers from characteristic regions of the 

 normal Sebright and of the castrated Sebright are shown in pairs. 



One of the first Sebrights that was castrated was a lighter bird than 

 the others. Its lighter color was partly due to the narrower outer 

 band of the laced feathers, (plate 6, figure 1,) and partly to the 

 lighter color of the yellow-brown center of the feathers. The bird had 

 a single comb, but as this crops up occasionally in some stocks of 

 Sebrights, it need not be interpreted to mean that the bird was impure 

 for color factors. After being castrated the bird changed over com- 

 pletely to cock-feathering and has remained in that condition for two 

 or more years. As shown in plate 5, figure 2, the plumage is 

 even more fully developed than in cock birds of some other breeds. 

 The comb and wattles are, however, shrunken and pale, as in a capon. 

 The bird is timid and scarcely or never crows. When killed (May 

 1919) no pieces of testes and no trace of testicular tissue at the old 

 situs were found. 



The details of the feathers are shown in plate 6, figures 1 and la, 

 where, in each instance, one of the old and one of the new feathers 

 from the same region are placed side by side. The feathers on the 

 head and hackle are yellow, even to the base. At the base of the 

 hackle — the so-called cape — a few feathers have a small black tip. 

 The feathers of the back are entirely yellow, except that where the 

 fluff begins there is some dark pigment. The saddle feathers are for 

 the most part all yellow, but a few have at the base, near the fluff, 

 black on each side. The tail coverts are long, with a black margin at 

 their tip. The tail feathers are long, mossy, and have a black tip. 

 The wing-bow feathers are all yellow, except the black fluff at the base. 

 The feathers on the crop are mostly yellow with black margin around 

 the end. Those on the breast lower down are yellow with black tip 

 and black fluff. 



There was another Sebright operated upon at the same time that was 

 a darker bird (as the original feathers show, plate 8, figs. 1 to 4). It had 



