. Poultry production. Poultry. ISO POULTRY PRODUCTION ni)()n tlic yolk. On the nineteeiitli day wliat remains of tlie yolk is drawn into tlie hody ca\ity. Tiiis apjiears to be tlie most critical day of the incubation ]:)crio(i, for as Payne' has shown, 20 per cent of tlie mortalit,\' ncciirring during the twenty-one days of the incubation period occur on the nineteentli day, and 4S ])er cent of the t-s. The respirator^' system changes completely on the twentieth day. Until that tune the alhui- tois functions as the chief res])iratory organ, and, in fact, as tlie excretory organ as well. With t
. Poultry production. Poultry. ISO POULTRY PRODUCTION ni)()n tlic yolk. On the nineteeiitli day wliat remains of tlie yolk is drawn into tlie hody ca\ity. Tiiis apjiears to be tlie most critical day of the incubation ]:)crio(i, for as Payne' has shown, 20 per cent of tlie mortalit,\' ncciirring during the twenty-one days of the incubation period occur on the nineteentli day, and 4S ])er cent of the t-s. The respirator^' system changes completely on the twentieth day. Until that tune the alhui- tois functions as the chief res])iratory organ, and, in fact, as tlie excretory organ as well. With the pipping of the shell imlmonary breathing begins. Fig. 91. Appearance of a chick ciiiijryo after forty-eight lioiira in an incnbator (Courlesy of Kan.^as Agiirnltnral iOx|jeiniirnt Station,) When formed the chick is placed in the egg with its head L)ent forward beneath the right wing and the legs brought up toward the head. The end of the ui)per mandible of the beak is equipped with a horny cap which bears a sharp point, and by means of this, while slowly revolving in the shell, the chick is able to press against the shell, chipping it in a circular l)ath around the large end of the egg, at the same time â Jour. Am. Inst, and in foul. IIuslj., vol. vi, No. 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 Lippincott, William Adams, 1882-1931; Card, Leslie Ellsworth, 1893-. Philadelphia, Lea & Febiger
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectpoultry, bookyear1921
