. Agricultural zoology. Zoology. The first half, which receives the blood, poor in oxygen, that is returned from the body, and sends it on to the lungs, lies on the right, and is termed the right half. The second half, which receives the richly oxygenated blood from the lungs, and pumps it to the various parts of the body, is termed the left half (Fig. 9 and explanation). In the arrangement just described, which is found in Mammals and Birds, the blood returning from the lungs is propelled with new force through the body, and therefore circulates very quickly, so that the various parts receive


. Agricultural zoology. Zoology. The first half, which receives the blood, poor in oxygen, that is returned from the body, and sends it on to the lungs, lies on the right, and is termed the right half. The second half, which receives the richly oxygenated blood from the lungs, and pumps it to the various parts of the body, is termed the left half (Fig. 9 and explanation). In the arrangement just described, which is found in Mammals and Birds, the blood returning from the lungs is propelled with new force through the body, and therefore circulates very quickly, so that the various parts receive a relatively large amount of oxygen in a short time. It is therefore intelligible that Birds and Mammals develop more warmth than Fish, They possess a special, constant body tempera- ture, somewhat different in difierent species, but usually lying between 98° and 104° Fhr., and they are called warm,- blooded animals. In Reptiles (snakes, FIG. of the Heart of a Reptile. }^fT'^' /tc.), the twO Between the right () and left ) haiVCS 01 the heart are ventricles Is a perforated partition. , „ j. i t ,• right anriole; !.:., left auricle; , nOt entirely Qistuict, vena cava, carrying back the blood which oinppfhAro to an r^Ti^nn'^™ has traversed the body into the right ^'^^^^ mere IS an Opening anricle; , pulmonary artery; , in the Partition - Wall puhnonary vein; .flo.,aorta. , , jjo/i-uiuiuii wdjj. between the two ven- tricles. As a consequence of this, the poorly oxygenated Fig. 9—Diagram of the Mammalian Heart. 1, right, 2, left ventricle; 3, right, 4, left auricle; 5, su- perior, 6, inferior vena cava; 7, pulmonary artery forking into branches for right and left lungs; 8, the four pulmonary veins; 9, the great body-artery (aorta); the arrows indicate the direction of the blood stream. Z. art. , Please note that these images are extracted from scanned page images that may have been digitally enhanced for


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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1894