104 PTERYLOGRAPHY. 



biserial limbs, which, at the bottom of the neck, give off a row of feathers to the axillary tract, and 

 pass upon the pectoral muscles under considerable divergence. Here each stem gives off a triserial 

 outer branch, which runs parallel to the main stem, and terminates in an obtuse extremity. The main- 

 stem itself, two feathers in width, at first somewhat approaches the crest of the sternum, then passes 

 more outwards, describes a moderate curve upon the belly, and terminates near the anus. The 

 weak axillary tract is simple and three feathers broad ; the long lumbar tract consists of two rows 

 of weak feathers, but the tibia is clothed with a homogeneous sparse plumage. In the wings I 

 found twenty remiges, of which the first is very small, whilst the second is equal to the seventh, 

 and the third, fourth, and fifth are the longest. The upper accessory wings (parapterum superius) 

 consist of seven feathers the lower accessory wings (parapierum inferius) are merely formed of 

 semiplumes, which are continued on the breast as far as the outer branch of the inferior tract, 

 forming a hook with it. The whole of the great wing-membrane beneath is a large space, which 

 is covered by the feathers of its anterior margin ; above it is half covered with feathers, and 

 the rest, as far as the axillary tract, is a space. The singular structure of the oil-gland in this 

 bird lias already been mentioned (p. 41); I will now describe it in more detail. It consists of 

 two almost completely separated, widely distant halves, the posterior ends of which are apparently 

 united only by cellular tissue ; these are seated upon a large pyriform membranous cavity, the acute 

 hinder end of which is stretched and held open by the tubes of the circlet of feathers which are 

 inserted in it. The vanes of these feathers are bent outwards posteriorly, and form the wide, 

 trumpet-like entrance to the cavity, in the base of which, opposite to the orifice, two small pits 

 may be observed, in which the numerous secretory tubes of each half of the gland open. The 

 gland exhibits no other cavity, but presents a radiating texture in its interior, from the course 

 taken by the canals of the gland. In the latter I found at all times a yellowish, inodorous oil; 

 but the cavity behind the gland contained, not in the males, but in the females at the breeding 

 season, and in the young nestlings, a thicker blackish fluid which diffused the most insupportable 

 odour, and is the cause of the ill name of the Hoopoe in this respect. This is merited, however, 

 only at the breeding season, and even then not by the male, but only by the female and young. 

 The latter, which I have repeatedly seen, possess a lax nest-clothing, the downy barbules of which 

 are seated upon the first barbs of the future contour-feathers, as I have ascertained most decidedly 

 by a very careful examination. These barbules, however, are wanting in all parts of the inferior 

 tract and on the wings, but they occur on all other parts which bear contour-feathers, issuing 

 from the apices of the latter. I was also struck by the very remarkably broad and snow-white 

 skin of the angle of the mouth in these young birds. 1 



Upupa africana and U. erythrorltyncha, which I likewise examined, agree exactly in all 

 their pterylographic characters with the European species, as does the second also in the form of 

 the oil-gland and the shape of the wings ; nevertheless, U. erytJirorhyncJiu has only nineteen 

 remiges, and the fourth, fifth, and sixth are the longest. There can consequently be no doubt 

 that this species, which is referred by Temvninck to Epimachus, and by Lichtenstein to Nectarinia, 

 belongs to the present genus. 2 The skeleton also, which I examined in the Museum at Frankfort, 

 shows it to be a Vpupa. 



In this respect the Hoopoe much more resembles the Passerinae than the other Picariae, the 

 young of which, especially those of Alcedo and Picas, usually possess a very slight dilatation of the 

 skin of the rictus. 



8 [Confer also Strickland's remarks ' Aun. Nat. Hist.' xii, p. 238 (1843), upon the affinities of 

 Ujn/pa and Irrisor. P.L.S.] 



