. Elements of the comparative anatomy of vertebrates. Anatomy, Comparative. COMPARATIVE ANATOMY thickened, and forms a main axis or stem (scapus), to which the barbs are attached on either side. The proximal or basal portion of the scapus which bears no barbs is called the quill {calamus), and the distal part, to which the barbs are attached, the shaft (rachis). The barbs together constitute the vane (vexilhim) (Fig. 14, F).. TalISm Fiu. 14.—Six Stagks ix the L)EVELorMEXT of the Feathek. (Mainly after Th. Studer.) Oil, dermis ; SM, stratum Malpighii; /SV, stratmn corneum ; SiP, .S'c\ extension
. Elements of the comparative anatomy of vertebrates. Anatomy, Comparative. COMPARATIVE ANATOMY thickened, and forms a main axis or stem (scapus), to which the barbs are attached on either side. The proximal or basal portion of the scapus which bears no barbs is called the quill {calamus), and the distal part, to which the barbs are attached, the shaft (rachis). The barbs together constitute the vane (vexilhim) (Fig. 14, F).. TalISm Fiu. 14.—Six Stagks ix the L)EVELorMEXT of the Feathek. (Mainly after Th. Studer.) Oil, dermis ; SM, stratum Malpighii; /SV, stratmn corneum ; SiP, .S'c\ extensions of these tissues into the featlier-papilla, Pap; FK, feather-germ ; F, F\ feather-follicle ; P, pulp ; Fal {SM^), folds of the Jlalpighian layer extending into the feather-germ, and enclosed externally- by the horny layer, HS (.Sf^) : both laj'ers are seen in the transverse section (0); F,Sp, quill of feather, which breaks up above into a tuft of rays or barbs (SSf) ; sec, .str, secondary rays (barbules) arising from the latter ; i?, rachis ; V, vexillum. For further details as to the different stages A-F, compare text. The barbules are so arranged on each barb as to make the latter resemble an entire feather in appearance. The barbs may become very closely united together by means of minute hooks on the barbules, so that an extremely strong and resistant though pliant structure is formed; this is especially the case in the large wing and tail feathers (rcmiges and rcdriccs). In many each quill of the ordinary feathers of the body bears two ^•exilla, the second being spoken of as the (ifteishaft (hiijuDxichis).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Wiedersheim, Robert, 1848-1923; Parker, William Newton, 1857-1923. London, Macmillan
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectanatomycomparative
