. The animal kingdom, arranged after its organization, forming a natural history of animals, and an introduction to comparative anatomy. Zoology. AVES. 155. Fi£. 68.—Sternal apparatus of t newly-hatched (.'hick. composed originally of five pieces : one medial (fig. 68, a), of which this salient lamina [known as the sternal crest, ridge, or keel] constitutes a part; two triangular anterior la- teral [termed costal processes] (b), for the attachment of the ribs ; and two forked posterior lateral (c), for the extension of its sur- face ; and the greater or less degree of the ossification [that is
. The animal kingdom, arranged after its organization, forming a natural history of animals, and an introduction to comparative anatomy. Zoology. AVES. 155. Fi£. 68.—Sternal apparatus of t newly-hatched (.'hick. composed originally of five pieces : one medial (fig. 68, a), of which this salient lamina [known as the sternal crest, ridge, or keel] constitutes a part; two triangular anterior la- teral [termed costal processes] (b), for the attachment of the ribs ; and two forked posterior lateral (c), for the extension of its sur- face ; and the greater or less degree of the ossification [that is to say, obliteration] of the notches of these last, and the extent of the interval which is left between them and their principal bone, denote the relative amount of vigour of flight in Birds. The [Eagles, Harriers, (the Falcons much more slowly, if indeed at all), and some other] diurnal Birds of prey, the Swifts and the Humming-birds, [the Parrots, and also the Storm-petrels,] lose, as they grow old, all traces of these unossified spaces. [In the Ostrich and its allies, the sternum is composed originally of only two pieces ; and the number likewise varies in those Birds which possess a sternal crest.] The fourchette [furcula, or " merry-thought" bone], (fig. 68, d), produced by the junction of the two clavicles, and the two stout abutments formed by the [huge] coracoid aphophyses (e), keep the shoulders apart, notwithstanding the opposing force exerted by the action of flying ; the fourchette, in particular, is commonly more stout and open, according as the flight of a Bird is vigorous.* (See fig. 67.) The wing, supported by the humerus (fig. 69 a,) fore-arm (b), and hand, which is elongated, and exhibits one digit and the rudiments of two [or (including the winglet o.) three] others (1,2,4) is furnished through- out its length with a range of elastic quills,which greatly extend the surface that resists the air. The quills ad- hering to the hand are named primar
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectzoology, bookyear1854
