. Poultry production. Poultry. 170 POULTRY PRODUCTION fluid called the amniotic fluid, which serves as a protection from shock and aUows the embryo to move about freely. The growth of the amnion constricts the connection of the yolk with the embryo to a narrow stem called the yolk stalk. This stalk corresponds to the umbilical cord in mammals. At about the thirtieth hour the heart of the chick has developed far enough to be observed to beat. Fig. 82. Two embryos (twins) developing on one yolk, thirty-two hours old. Magnified. (Courtesy of Iowa Experiment Station.) Near the middle of the second
. Poultry production. Poultry. 170 POULTRY PRODUCTION fluid called the amniotic fluid, which serves as a protection from shock and aUows the embryo to move about freely. The growth of the amnion constricts the connection of the yolk with the embryo to a narrow stem called the yolk stalk. This stalk corresponds to the umbilical cord in mammals. At about the thirtieth hour the heart of the chick has developed far enough to be observed to beat. Fig. 82. Two embryos (twins) developing on one yolk, thirty-two hours old. Magnified. (Courtesy of Iowa Experiment Station.) Near the middle of the second day a blind sac begins to push out from the posterior end of the alimentary tract, which grows rapidly until it completely covers the embryo at about the ninth day and has come in close contact with the shell membrane. It is abundantly supplied with blood- vessels and, although it is outside the body of the embryo, serves as the organ of both respiration and excretion until. 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. Philadelphia, Lea & Febiger
Size: 1582px × 1578px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectpoultry
