FIG. 3. Castrated male originally hen-feathered (292), nearly black in color, as shown by the individual feathers of plate 7, figure 2. After castration the bird has become red above, with black iridescent tail-coverts, and deeper yellow (or red) below. FIG. 4. Castrated F₁ male, originally like figure 1. Note especially the change in color of the whole upper surface that has become red, like that of the jungle-fowl. The tail-coverts have grown long and are now iridescent black. The breast has changed least, but is a richer yellow. The comb and wattles and ear lobes are shrunken, as in all capons. PLATE 3. FIG. 1. A castrated Sebright male. The operation was performed on a juvenile bird; the drawing was made a year later. The bird is typical as to the change in color that takes place in the Sebright. He was darker red than the bird shown in plate 1, figure 4. The red was more mahogany than the picture shows. The original feathers were like those in plate 6, fig. 2 (there erroneously referred to as those of light-colored Sebright). FIG. 2. An F₂ hen-feathered very dark male. The condition of his plumage at the time of the operation is shown in this figure. The change that took place after castration is shown in the next figure. FIG. 3. The change that took place in the bird drawn in figure 2 is shown here. The whole upper surface has become red, except the tail-coverts, which are iridescent black. Note also the change in color on the wing-bow. For the details of the feathers see plate 9, figures 1, 1_a_. FIG. 4. A castrated F₂ bird that had been hen-feathered and had changed over to cock-feathering, as shown here. The color and the details of the original hen-feathering are shown in plate 9, figures 2 and 2_a_. 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 F₁ male. This bird had just reached maturity and was younger than the one drawn in plate 2, figure 1. FIG. 6. An F₁ 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.