. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. 310 ZOOLOGY hand and foot considerably modified from those of an animal which uses all the appendages for locomotion. The digestive tract is also much like that of man. (See page 330.) Organs of Digestion. — The digestive glands, and the salivary, gastric, intestinal, and pancreatic glands have nearly all the same position and functions. The glands which act upon starch are better developed in the rabbit than in man because of the predominance of starchy foods used by the rabbit. The intest
. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. 310 ZOOLOGY hand and foot considerably modified from those of an animal which uses all the appendages for locomotion. The digestive tract is also much like that of man. (See page 330.) Organs of Digestion. — The digestive glands, and the salivary, gastric, intestinal, and pancreatic glands have nearly all the same position and functions. The glands which act upon starch are better developed in the rabbit than in man because of the predominance of starchy foods used by the rabbit. The intestine is longer than in flesh-eating animals. Circulation. — In all mammals (of which the rabbit is an example) the blood in its circulation passes through a four-chambered heart. There is a system of closed blood tubes which, according to the position and function, are named arteries, veins, and capillaries. The whole process of circulation is identical with that process in man (see Circulation, page 350). The lungs and heart are separated from the lower part of the body cavity by means of a thin-walled plate of muscle, called the diaphragm. This dia- phragm occurs in all mammals. Oxygen is taken up by the blood and respiration takes place in a similar manner to that process in man. In like manner the organs of excretion of nitrogenous waste, the skin and kidneys, eliminate the waste from the body in the same manner as it is done in man. Nervous System. — The brain and central nervous system of the rabbit are well developed. A brain, which has a large cerebrum and other char- acteristics of the brain of man, supplies sense organs through twelve cranial (brain) nerves (see The Nervous System, page 400). The senses, especially those of sight and hearing, are also highly developed and are very acute. We have seen that the eyes are so placed that the animal is able to look to the sides and behind without turning the head. Organs of taste, the taste buds, such as are found in m
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