. Animal physiology. Physiology, Comparative; Physiology, Comparative. 480 EQUILIBRIUM OF ANIMALS. pieces can be seen), and p, pi, pt, the three phalanges of the toes, of which the last is enveloped in the hoof, which is nothing else than a large nail enclosing the whole extremity of the toe. In the Horse this consolidation is carried still further than in the Ruminantia; for it has only one toe in each foot; but we see the rudiment of an additional bone in the metatarsus (b, Fig. 219), which is commonly termed the splint bone. 653. But when an animal is supported upon two feet only, whatever
. Animal physiology. Physiology, Comparative; Physiology, Comparative. 480 EQUILIBRIUM OF ANIMALS. pieces can be seen), and p, pi, pt, the three phalanges of the toes, of which the last is enveloped in the hoof, which is nothing else than a large nail enclosing the whole extremity of the toe. In the Horse this consolidation is carried still further than in the Ruminantia; for it has only one toe in each foot; but we see the rudiment of an additional bone in the metatarsus (b, Fig. 219), which is commonly termed the splint bone. 653. But when an animal is supported upon two feet only, whatever may be their degree of separation from each other, the base of support cannot have sufficient extent, unless the extremities touch the ground by a considerable surface. This is the case with the foot of Man, and still more with that of many Birds which habitually stand upon one leg. In order that an animal may hold itself in equilibrium upon a single limb, it is necessary that the foot should be placed vertically beneath the centre of gravity of the body; and that its muscles should be so arranged, as to permit it to keep this limb inflexible and immovable. Man can accomplish this; for the centre of gravity of his body is about the middle of the pelvis ; and to place this vertically over the foot, it is sufficient for him to bend himself a little from the side which is not sup- ported. But the greater number of Quadrupeds are destitute of the power of doing this ; and a large part of them cannot even raise themselves on their hind legs, on account of the direction of these members relatively to the trunk ; or if they can do so for an instant, they cannot maintain themselves in this position. The reason of this is very simple. The base of support, on account of the smallness of the feet, is very narrow, and the centre of gravity of the body is placed nearer the front, towards. Fig. 220.— Please note that these images are extracted from scanned page images that may have
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Keywords: ., bookauthorcarpenterwilliambenja, bookcentury1800, bookdecade1840
