THE CURSORIAL BIRDS. 119 



unquestionably the total absence of the oil-gland. Along with the power of flight both remiges 

 and rectrices are wanting ; in the Indian Cassowary alone the rigid shafts of the former are 

 still indicated in the form of thick, long, powerful spines. 



This is all that I have to say upon the pterylosis of the Cursorial Birds, all the species of which 

 I have repeatedly examined, even in a fresh state. But the first coat of the young birds presents 

 material for some further remarks. This consists, as in all cases, of truly downy barbs, which 

 are seated upon the apices of the future contour-feathers. I have ascertained the mode in which 

 this union is effected in Dromeeus nova hollandiee, of which, as also of Rhea americana, I have 

 been able to examine very young examples, only two or three weeks old. I found that the down 

 is at first a true perfect feather, which is inserted into the same follicle from which the contour- 

 feather subsequently grows. Each oi these down-feathers in Dromceus has two shafts of the same 

 structure, and analogous in their ramification to those of the future contour-feathers, but the 

 number of barbs is much less, at the utmost six or eight. The two uppermost barbs, in which, 

 as in a sort of fork, both the main and after-shafts terminate, are for the most part not at all 

 feather-like, but are simple linear lanceolate bristles, finer towards the end, round, flat 

 beneath, and so long as not iinfrcquently to exceed the whole down-feather in length. The next 

 two or three barbs also bear similar but much smaller bristles. Hence arises the apparent hairy 

 covering possessed by the young Cassowary, which is usually well expressed in representations of 

 it. At the base each down-feather has a small tube, with the inferior open and cleft extremity 

 of which the extreme tips of the following contour-feathers (both shafts and barbs) are amal- 

 gamated, so that, as soon as the contour-feathers sprout forth, the down-feathers are suspended 

 upon them, and are cast off, or fall of themselves, only at a later period. The structure in Ehea 

 is exactly the same ; but as this genus has only a single shaft in each feather, the down is also only 

 provided with one shaft. 1 



1 I have had the opportunity of examining the downy covering of an African Ostrich at the utmost 

 a few weeks old. It presented precisely the above-described structure of feathers ; and although, on 

 account of the youth of the specimen, no trace of the future contour-feathers could be detected, and 

 therefore the down-feathers themselves were still inserted in the skin, I have no doubt that in this 

 genus also they are elevated and thrown off by the contour-feathers. The uppermost four or six 

 barbs of these down-feathers ran out into long, linear-lanceolate, horny, perfectly naked processes, 

 destitute of barbules, which were bent down on the body, and lightly covered the true downy coat, at least 

 upon the trunk. Both the down-feathers and these appendages of theirs were partly yellowish-gray 

 and partly black ; that is to say, some of the feathers were entirely of one colour, others of the other, 

 and they stood intermixed with each other. Even on the head and neck this young Ostrich had 

 a general setiform covering, which presented a very definite coloration and pattern. The vertex and 

 forehead were yellowish-brown, the throat and fore part of the neck reddish- white, the hinder part of the 

 neck more grayish, and rows of elongate black spots ran down the sides of the neck. On the body 

 black and white feathers stood intermixed, but the former predominated above and the latter on the 

 sides. The sides of the trunk in the vicinity of the thighs were naked, but both the thigh and the tibia 

 were covered by the fine setigerous downy coat. BURMEISTER. 



