222 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



and their unsheathed tips. The papillae of the tail feathers are 

 only 8 millimeters long and as yet do not show through the down. The 

 feather papillae of the head and tail are the last to unsheath. 



In chicks 13 days old the "pinkish cinnamon" of the tips of the 

 feathers of the dorsal tracts has faded to a "pinkish buff," and some 

 of the feathers approach a "tilleul buff." Freshly unsheathed 

 feathers of the crown are "pinkish cinnamon." Black markings 

 have faded to a "fuscous-black" or "dusky neutral gray"; yellowish 

 color of the breast feathers of the younger stages now faded to gray 

 tinged with yellow. The juvenal plumage is rapidly replacing the 

 ]iatal down in all parts of the body. The yellowish-gray breast 

 feathers are barred with "dusky neutral gray." As previously noted, 

 one of the two birds died from exposure to great heat at this time 

 and the remaining descriptions are based on one bird. 



At the age of 15 days the down is ragged in appearance but is 

 still prominent on the breast, sides of the head, wing coverts, and 

 region of the tail. The down is worn off the feathers in the region 

 of the crown and scapulars. Feathers of all tracts of the juvenal 

 plumage are partially unsheathed. When the young are handled 

 there are numerous particles of the feather sheaths that scale off. 

 The wings exhibit a marked development. The tips of the under 

 tail coverts recently unsheathed are ivory colored. The down per- 

 sisting at the tips of the feathers comes off with the slightest pull. 

 The pupil of the eye appears bluish black and the iris has changed 

 to a "Van Dyke brown." 



When 17 days old the sixth primary has now proceeded with 

 unsheathing so that the white patch is 13 millimeters in extent. 

 Tarsus and toes are "blackish plumbeous," bill is a "dusky purplish 

 gray," eyelids are "dark olive-gray"; otherwise the markings are 

 similar to those of the 15-day-old bird. 



When 20 days old a relatively small amount of down remains, but 

 a few filaments can be seen on the tips of some of the crown feathers, 

 sides of neck, and breast. Feathers of the wings are growing fast 

 and are so heavy from the large amount of blood and large sheaths 

 that the wings rest on the surface of the roof, the bird being unable 

 to support them. The wings are frequently outstretched, apparently 

 to relieve the uncomfortable sensation produced by rapid growth 

 of the feathers. Bristlelike feathers now appear around the base 

 of the beak. The fifth primary is grown so that the white patch 

 is beginning to unsheath, and the base of the fourth primary shows 

 white area on sheath, which is destined to form part of the white 

 patch on the wing of the fully grown young. The white on the 

 sixth primary made its first appearance in the l7-day-old chick. 



At this age the crown is "dusky neutral gray" or black, the feathers 



