. Zoölogy [microform] : descriptive and practical. Zoology; Zoologie. V i il: I the ceca. The terminal portion of the digestive tube is widened, and is called the cloaca. It receives three sets of products, (i) the residue of digestion, (2) the eggs,and (3) the excretion of the kidneys. The Circulatory System of the Pigeon.—The circula- tion of blood is very rapid in birds because of their great activity. The j jart is proportionally large; it is com- pletely divided into two halves, so that the blood moves through one half of the heart from the lungs to the body, and through the other half fr
. Zoölogy [microform] : descriptive and practical. Zoology; Zoologie. V i il: I the ceca. The terminal portion of the digestive tube is widened, and is called the cloaca. It receives three sets of products, (i) the residue of digestion, (2) the eggs,and (3) the excretion of the kidneys. The Circulatory System of the Pigeon.—The circula- tion of blood is very rapid in birds because of their great activity. The j jart is proportionally large; it is com- pletely divided into two halves, so that the blood moves through one half of the heart from the lungs to the body, and through the other half from the body to the lungs, being pumped twice in the circuit instead of once as in fishes. An important point to note is that the aorta turns to the right instead of to the left as in our bodies. How the Pigeon Breathes. — Respiration is exceedingly active in a bird. Imagine yourself taking such violent ex- ercise as that required for a bird to fly through the air at the rate of a mile a minute. Would you not be "out of breath " ? The bird's lungs are of fair size; in addition there are air sacs in all parts of the body, communicating with the lungs, the bronchial tubes continuing on through the lungs into these sacs. The lungs do not lie free in the body cavity as in our bodies, but are attached to the dorsal wall, fitting closely between the ribs. The air sacs are also in communication with the hollows of the bones, adds to the buoyancy. The temperature of birds is higher than that of any other animals, being about 110° F. The movements of respiration in birds is peculiar, in that expiration is accomplished by active muscular effort, and inspiration by elastic reaction,—just the opposite of the processes of our bodies. The Excretory System of the Pigeon. —The lungs serve us organs of excretion, throwing off carbon dioxid. The ^ V. %^mr^0mmm. m^.m^^:^'^. Please note that these images are extracted from scanned page images that may have been digitally
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1903
