Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges . a Fig. 336.—An incubated vitellus of the jackdaws egg; A, of the na-tural size ; B, magnified—a, vitellary membrane ; b, b, b, halones ; c,embryo ; d, area pellucida, e, area vasculosa. (^Compare with figs. 330and 333.) 306 breadth posteriorly, and terminating in two (fig. 337, d, f) or three (fig. 337, e] crura ; theseare the future great venoustrunks, which as yet are lost in-sensibly in the germinal mem-brane. Even at this
Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges . a Fig. 336.—An incubated vitellus of the jackdaws egg; A, of the na-tural size ; B, magnified—a, vitellary membrane ; b, b, b, halones ; c,embryo ; d, area pellucida, e, area vasculosa. (^Compare with figs. 330and 333.) 306 breadth posteriorly, and terminating in two (fig. 337, d, f) or three (fig. 337, e] crura ; theseare the future great venoustrunks, which as yet are lost in-sensibly in the germinal mem-brane. Even at this period un-dulating motions, rhythmicalcontractions of the heart, maybe perceived, by which thesomewhat wavy appearance ofthe organ is produced; the sameclear or nearly colourless fluidis in motion in the heart as inthe vessels in the heart occupies the wholespace from the involucral pointof the germinal membrane tothe cranial end of the embryo,Fig. 337.—Anterior end of an ancl is consequently, when theembryo scarcely of greater age embryo is contemplated fromthan that of fig. 330, seen from below, covered by the part ofthe abdominal (the vitellary) as- the serous membrane which atpect, to show the first formation ,1 ? .-, • -, of the sacculate heart, a, with the Sam6 tmie f°r^S the involuits immerging vascular (venous) crum capitlS. The embryo,trunks, d, e, f; b,
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1870
