Rensselaer Republican, Volume 19, Number 7, Rensselaer, Jasper County, 21 October 1886 — Locomotion of Animals. [ARTICLE]

Locomotion of Animals.

The lizards andcrocodiles present diversified organs of motion. Amongst the former, the gecko is supplied with a peculiar pneumatic apparatus in the feet by means of which it has the power of exhausting the air beneath the toes, and is thus enabled to climb vertically the smooth surface of walls, and to walk in an inverted position along the ceilings of rooms. This provision is advantageous to the animal when pursuing the insects on which it preys. In many of the lizards, such as the chameleon, the tail is in like manner used to secure them ,mojQ,®teadily oh oKuvxxtss "’tfiehand is furnished with two thumbs oppbsite to three fingers, and the foot with three thumbs opposed to two fingers. By this arrangement the animal is endowed with considerable facility in taking hold of the branched, being thus provided, as i tuyere, with hands. The crocodiles are furnished with four legs, and can walk - and run on solids like mammiferous quadrupeds. The bones of the neck and back are, however, so locked together that they cannot turn or twist the body sideways, except in an exceedingly limited degree. They are consequently obliged, when moving rapidly, to keep in nearly a straight line, and from this cause may be easily avoided by man, should he' be pursued by one of these amphibious monsters. The tortoises are slower than the crocodilean reptiles. Like the latter, they cannot twist the body on itself; and the ponderous case within which they are enclosed, and w’hich they drag along with the body, resist the freedom of motion of the legs at those points where they pass out of their solid case. This renders their pace exceedingly slow. Their carapace or shield serves, however, to protect them from injuries arising from the tread of heavy quadrupeds, and is essentially use fid to them during their occupation of burrowing. They move on the principles of mammiferous quadrupeds. We have seen that the croco-. diles and tortoises possess little or no power toturn their bodies to the right or to the left; and also that it occupies the last-named animals a long time to change their course from one direction to another. Serpents, on: the contrary, have a very great range of lateral motion; and indeed, destitute as they are

of legs, were the bones of the back as immovable as those of the tortoise, they would be deprived of the power of locomotion; but beimj endowed with very great mobility of the vertebra;, they are enabled, notwithstanding the want of legs, to climb trees, to run with considerable speed on the ground, and to swim rapidly in rivers and lakes. The scales, which are seen on the belly of the animal enable it to lay hold of fixed objects on the ground, and by the alternate elongation and contraction of the body, it glides along with great celerity’ There are several ways in which serpents move, but the most common are the vertical and lateral modes. The frog, like the crocodile and tortoise, haa not the power of twisting its body; it moves by a succession of leaps. It is said that the bull-frogs, which are abundant near the great lakes of North America, van leap six feet at a bound, and repeat these leaps so rapidly, that they cannot bo captured without great difficulty. They will leap over walls five feet in height. Thehyla; or treefrog, has each of its toes furnished with a concave disc, which acts as a sucker; and by this means the animal has the power of laying hold of the branches of trees with considerable force, and can leap from branch to branch with great agility. It is by means of the hind legs, which are much longer than the anterior, that the body is projected; the movements are performed on the same principle as those of the kangaroo and boa.