| OCR Text |
Show 1901.] PTERYLOSIS OF THE GIANT HUMMING-BIRD. 321 successively shorter, the outermost having only about five feathers. The median coverts each bear two tiny plumes at the base. There are several rows (about five) of marginal feathers which curve round on the shoulder to join the strong humeral patch. On the ventral side of the wing there is a complete series of major coverts, including an aquintocubital covert, and there is also an equally complete series of median coverts. There is one row of minor coverts together with a few others on the arm, not very regularly disposed. Text-fig. 82. Wing of Caprimulgus macrurus, dorsal view. c.r., carpal remex, with its major covert. The variations in the pterylosis of the wing are too numerous and too little known to justify us in drawing much from a close comparison of these types. They all three possess wings of comparatively simple structure, that of the Humming-bird being the most so, that of the Goatsucker the least. The wing of the Goatsucker is aquintocubital, with the apparently interstitial coverts present both above and below ; in the Humming-bird we see one only on the dorsal side; in Collocalia there is no sign of either. The median coverts of the primaries on the dorsal side are interrupted alike in the Goatsucker and the Swift; in both of these birds, and especially the latter, the minor coverts of the cubitus and the patagial feathers are much more numerous than in the Humming-bird. THE PTERYLOSIS OF THE REST OF THE BODY. In Patagona the general feathering of the back of the head, formed by the convergence of the bands above described, and supplemented by additional feathers on the occiput between the hyoid cornua, divides at the nape of the neck to run down on each side of a great posterior cervical apterion, fully an inch long, and occupying all the back of the neck nearly to the shoulders. The middle of the back is occupied from the shoulders to a little way in front of the oil-gland by a somewhat broad, lanceolate, dorsal apterion. The rest of the back is covered by a broad dorsal feather-area, which in front divides into two very narrow feathered strips that border the posterior cervical apterion, and merge halfway up the neck with the lateral cervical feat her-tracts. |
