. Animal life in the Yosemite; an account of the mammals, birds, reptiles, and amphibians in a cross-section of the Sierra Nevada. Zoology. RATTLESNAKE 649 both of these instances the snake had swallowed its prey head foremost. But a case has been reported by Dr. Barton W. Evermann (1915&) in which a rattlesnake killed near Cascade Falls (west of the lower end of Yosemite Valley) on July 15, 1914, contained an adult Mariposa Chipmunk which it had swallowed tail first! "The head of the chipmunk was toward the snake's head, and its legs, tail and fur all lay back toward the snake's tail
. Animal life in the Yosemite; an account of the mammals, birds, reptiles, and amphibians in a cross-section of the Sierra Nevada. Zoology. RATTLESNAKE 649 both of these instances the snake had swallowed its prey head foremost. But a case has been reported by Dr. Barton W. Evermann (1915&) in which a rattlesnake killed near Cascade Falls (west of the lower end of Yosemite Valley) on July 15, 1914, contained an adult Mariposa Chipmunk which it had swallowed tail first! "The head of the chipmunk was toward the snake's head, and its legs, tail and fur all lay back toward the snake's tail, smooth and in perfect order.''. Fig. 65. Sketch of head of Pacific Eattlesnake, showing important parts of the anatomy which function in the bite and poisoning by this snake. The action of the poison apparatus is as follows. As the snEike moves its head forward to strike a victim, be it man or animal. Muscle 1 (spheno-pterygoid) is contracted. This pushes forward the tooth-bearing bone preceding it and this in turn rocks forward the bone which carries the fang and causes the fang to come in line with the strike of the head. After the fang has entered the body of the victim, Muscle 1 relaxes and Muscles 2 and 3 (external pterygoid and spheno-palatine) contract, drawing the fang more deeply into the flesh. Then Muscle 4 (anterior temporal) contracts, bringing up the lower jaw and at the same time compressing the poison gland so that the poison is forced along the duct, through the fang, and into the flesh of the victim. Then the whole musculature of the head and neck relaxes, the head and fangs are drawn away from the victim and the fang is depressed again. This whole series of actions occupies but an instant. The fang is shown partly elevated. Normally it lies close to the roof of the mouth and is covered by a membrane not shown in the drawing. When the fang is erected, preparatory to biting, this membrane is folded down at the base of the fang and directs the poison as it lea
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Keywords: ., bookauthorgr, bookcentury1900, bookdecade1920, booksubjectzoology
