The hand : its mechanism and vital endowments, as evincing design / by Charles Bell.

  • Bell, Charles, Sir, 1774-1842.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: The hand : its mechanism and vital endowments, as evincing design / by Charles Bell. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    the foot; and as a division of the flexor tendon runs to each, the spring must be increased as the animal starts from its crouching posture. The two lateral toes of the hog are short, and do not touch the ground, yet they must serve to sustain the animal when the foot sinks. In the rein-deer, (fig. p. 64,) these toes are strong and thick, and by projecting backwards, expand the foot horizontally—thus giving the animal a broader base on which to stand, and, on the principle of the snow-shoe, adapting it to the snows of Lapland. These changes in the size, number, and place of the metacarpal and phalangeal bones, the sys- tematic naturalist will call gradations; I see only new proofs of adaptation,—of the same system of bones being applicable to every circumstance or condition of animals. I have explained why the bones of the elephant's leg should stand so perpendicularly over each other; but there is also a peculiarity of structure in the bones of its foot. In the living animal, we see only a round pliant mass as a foot, resembling the base of a pillar, or that of the trunk of a stately tree. But when we examine the bones, we find the carpus, metacarpus, and phalanges applied to a very different use from what we have hitherto noticed; they are not connected with a moveable radius, and have no individual motion, as in the carnivorous animal—they serve merely to expand the foot, and give to the broad base of the column a certain elasticity. In the sketch (page 40) I have placed the bones of the anterior extremity of the camel in contrast with those of the elephant. The camel's foot having no such disproportionate weight to bear as that of the elephant, lightness of motion is secured by the oblique direction of its bones, as well as by the position of the bones of the shoulder, which we have already noticed. But there is much to admire besides in the foot of the camel; although the bottom be flat and hard, like the sole of a shoe, yet, between the tendons and the horny sole, a cushion is interposed, so soft and elastic that the animal treads with the greatest lightness and security. The resemblance of the foot of the ostrich to that of the camel has not escaped naturalists. In the bird, the same soft- ness and pliancy of the sole are provided for by means resem- bling those in the quadruped, but by another adaptation of the