DESCRIPTION OF PLATES. 107 



PLATE 4. 



FIG. 1. One of the original Black-Breasted Game males used in the breeding experiments. 



Compare with colored drawing, plate 1, figure 1. 

 FIG. 2. A Black-Breasted Game hen used in the breeding experiments. Compare with 



colored drawing, plate 1, figure 2. 

 FIG. 3. A Sebright male. The bird was used in the later back-crosses and not in the original 



experiments. He is typical of his breed. 



FIG. 4. A Sebright female. One of the birds used in the original experiments. 

 FIG. 5. An Fi male. This bird had just reached maturity and was younger than the one 



drawn in plate 2, figure 1. 

 FIG. 6. An Fi hen of the same age as the last. The pattern changed a little as the bird 



became older. 



PLATE 5. 



FIG. 1. An adult Sebright male for comparison with the next figure. 



FIG. 2. A castrated Sebright male. This photograph shows the same bird from which the 

 drawing, plate 1, figure 4, was made. It is the lighter colored bird referred 

 to in the text. 



FIG. 3. One of the two Fi castrated birds. For comparison see the colored drawing in 

 plate 2, figure 4. 



FIG. 4. A castrated Sebright. This bird is darker, and in this sense more typical than 

 figure 2. 



FIG. 5. One of the castrated Sebright males which at one time after castration was as 

 extremely cock-feathered as figure 2, but slowly "went back" towards hen- 

 feathering, as the figure shows especially in the hackle and saddle. The 

 details are much better shown in the feathers photographed in plate 8, figures 

 1, 2, 3, 4, la, 2a, 3a, 4a, 16, 26, 36, 46. 



FIG. 6. The same bird was opened and the regenerated pieces of the testis removed. He 

 returned later, as shown here, to full cock-feathering. 



PLATE 6. 



FIGS. 1, IA. Typical old (1) and new (la) feathers (after castration) of the same bird. This 



is the "lighter" male drawn in plate 1, figure 4, and photographed in plate 



5, figure 2. 

 FIGS. 2, 2 A. Typical old (2) and new (2a) (after castration) feathers of another Sebright. 



This bird developed after castration darker feathers than did the last bird. 



Its feathers were more like those that other castrated Sebrights developed. 



Legend on plate 6 erroneous as far as 2 and 2o are concerned. 



PLATE 7. 



FIGS. 1, IA. Typical old (1) and new (la) (after castration) feathers of an FI bird. (See 



plate 2, figures 1 and 4.) 

 FIGS. 2, 2A. Typical old (2) and new (2A) (after castration) feathers of bird shown in plate 



3, figures 2 and 3 (No. 292). 



PLATE 8. 



Typical feathers of "dark" Sebright (1, 2, 3, 4) that after incomplete castration changed to 

 cock-feathering (la, 2a, 3a, 4a), then later, as pieces of the testes that had been 

 left behind in the old situs regenerated, began to go back towards hen- 

 feathering (16, 26, 36, 46). The bird was then opened again, and the regener- 

 ated pieces removed, when it again became cock-feathered (Ic, 2c, 3c, 4c), 

 and has so remained for more than a year. 



