Hen-feathering is dominant to cock-feathering. As shown in plate 2, the F₁ male is almost as completely hen-feathered as is the male Sebright. There is a somewhat greater color difference between the F₁ male and F₁ female than between the Sebright male and female. Two F₁ birds were castrated for me by Goodale. At the time of operation, in the autumn of 1916, both birds were full grown, (plate 2, figure 1). After molting the old feathers, both birds appeared as shown in plate 2, figure 4. Each is completely cock-feathered. The plumage has also undergone a remarkable change in color. In general, the color change is from yellow and black to reddish yellow. The greatest change is over the upper surface. The sickle, covert, and tail feathers are well formed and have now become iridescent black. The breast has changed least of all. One bird died February 12, 1919. When opened there was found on the left side a small white lump; on the other side almost nothing. The lump was found to consist of testicular tubules with loose glandular cells on its walls. The extent to which the change has taken place is best shown by comparison of individual feathers from identical regions--one before and one after the new feathers (taken out two years later) have come in (plate 7). The contrast between the old and new feathers of the hackle, saddle, back, and wing-bow are the most striking. In all of these the new feathers have become red on the exposed portion and the margin is free from barbules, as in the cock bird. The increase in size and change in shape of these feathers is remarkable. Equally great is the change in the tail-coverts that grade into those of the saddle at the base. The two median coverts or sickle feathers are longer than the tail and much arched. They are jet black with a purplish iridescence and with a yellow-red shaft. The tail itself has also changed; it has lost its stippling, and has become black like the coverts. The increase in length of the tail feathers is as remarkable as the increase in length of the coverts. A detailed account of these changes follows: F₁. 1. The head feathers are yellow with black base that shows through on the head. 2. The hackle feathers are yellow with black base (showing through on neck). 3. The red feathers of the back are penciled. There is a black band, especially around tip just inside of the margin. 4. The saddle feathers are much like those of the back, much stippled in center. The border is more distinct. 5. The tail coverts are similar to those of the hen. 6. The tail feathers are black, and with exception of the lower feathers they are partly stippled. 7. The wing-bow feathers are penciled like those of the back. 8. Feathers on crop yellow with black spot at tip; those lower down on breast have a bigger spot. CASTRATE. 1. The feathers are entirely red. 2. The hackle feathers are entirely red.