. Poultry production. Poultry. 184 POULTRY PRODUCTION Near the middle of tJje second (la>- a Ijlind sac Ijegiiis to piisli out from the jjosterior end of the aUmentary tract, wliicli grows rapidly until it completely covers the embryo at ahout the ninth day and has come in close contact with the shell membrane. It is aLundantly supplied with blood- vessels and, although it is outside the body of the embryo, serves as the organ of both respiration and excretion until the chick commences to pip the shell and the lungs and kidneys of the chick commence to function. It is the veins of this alla
. Poultry production. Poultry. 184 POULTRY PRODUCTION Near the middle of tJje second (la>- a Ijlind sac Ijegiiis to piisli out from the jjosterior end of the aUmentary tract, wliicli grows rapidly until it completely covers the embryo at ahout the ninth day and has come in close contact with the shell membrane. It is aLundantly supplied with blood- vessels and, although it is outside the body of the embryo, serves as the organ of both respiration and excretion until the chick commences to pip the shell and the lungs and kidneys of the chick commence to function. It is the veins of this allantois which are seen radiating horn the embryo at the first testing, about the seventh day Fig. 89. irauce ((_'oiii a chick emijryo after thirty-six l;iours in : sy of Kansas Agiicultural IO\|)ri inicnt St; I'lllialur, (jf incubation, and wdiicli may be noted plainly at the second testing, about the fourteenth day. As soon as the chick pips the shell, pulmonary circulation starts and the allantois ceases to function, begins to degenerate, and is left behind in the shell at hatching. Up to the sixth or seventh day there is nothing aliout the chick emljryo that would help one to distinguish it from the embryo of any other animal. At this time the legs and wings l)cgin to take a recognizable form. The body, which has been very small in proportion to the head, begins to develop. 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
