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THE

POPULAR SCIENCE

MONTHLY.

JANUARY, 1874.

FEW

CONCERNING SERPENTS.

BY ELIAS LEWIS, JR.

EW animals are more universally feared and detested than serpents. Their presence startles us, however inoffensive they may be. Nor can the gracefulness of their motion, or beauty of color, conquer the discontent we feel when we see them gliding in our path, or coiled and glistening in the sunshine, in which they delight. The enjoyment of many a summer's ramble has been impaired from this cause, and we fear our article may be as distasteful to many persons as are the objects of which it treats. But we may remember that serpents, no less than more attractive creatures, are important in Nature's economies. Their structure is a marvel of mechanical adaptation, less complicated, perhaps, but as perfect in every detail as is that of mammals and birds, and the mechanism which rolls the human eye is not more complete, and scarcely more wonderful, than that which moves the fangs of a viper. Perhaps, in the study of Nature, we should estimate objects by their fitness, rather than by their attractiveness or beauty.

...

"The serpent," observes Prof. Owen, "is too commonly looked down upon as an animal degraded from a higher type. . . . But it can outclimb the monkey, outswim the fish, outleap the jerboa; it has neither hands nor talons, yet it can outwrestle the athlete, and crush the tiger in its embrace." Serpents, in their mode of locomotion, are creeping animals, as their name implies, and constitute an order of the great class Reptiles. This term also implies creeping, but includes orders of animals which have limbs for locomotion, and do not creep. Of these, turtles, lizards, and crocodiles, are familiar instances; so that animals of several species, which run, walk, or swim, are included in the same class with those which creep. All of these, however, are cold-blooded, the temperature of the body differing but few degrees from that of the surrounding air or water. Their coldness is always

VOL. IV.-17

obvious to the touch, and this is true with those found in hot as well as in temperate climates, and adds greatly to their repulsiveness.

FIG. 1.

Of serpents, their general form and structure are the same. Their bodies are rounded and elongated, and covered with a scaly skin. The vertebral column is continuous with the length of the body, and is divided into joints from 200 to 400 in number, but in the large pythons (Fig. 1), as stated by Dr. Carpenter, 422 vertebral joints have been counted. To about 360, or of these, were attached pairs of movable ribs. A rattlesnake, with 194 vertebræ, had 168 pairs of ribs. The vertebræ of the serpent are united by a most perfect balland-socket joint, and the ribs are joined to the vertebræ in a similar manner. These, held and worked by complete food muscular adjustment, give to several their wonderful flexibility, strength, and crushing power.

The well-known boa-constrictor, and the aboma, or ringed boa of South America (Fig. 2), are illustrations of this class of serpents, the term constrictor being given from their power to close upon and compress whatever

is within their folds.

The structure of the backbone of a serpent has direct relation to its locomotion, for it is without limbs, and rudiments of pelvic bones are found only in the boas, pythons, and a few other species. But, where the type shades off into allied reptilian forms, the rudimental limbs are developed and promi

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nent.

We read that the curse pronounced upon the serpent was, "upon thy belly thou shalt go," and the inference seems to be that, previous to that time, its mode of progression was not upon its belly. This would imply a great anatomical change in the structure of the creature at the time in question, a change which, so far as we are aware, is not proved by paleon

PORT NATAL ROCK-SNAKE, OR PYTHON.

tological research, and the expression is probably a figurative one, as observed by Dr. Buckland. Serpents progress by the "foldings and windings they make on the ground," and the stiff, movable scales which cross the under portion of the body; but the windings are sideways, not vertical.

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The structure of the vertebræ is such, that upward and downward undulations are greatly restricted, and many illustrations, showing sharp vertical curves of the body, are exaggerations. Most persons have seen snakes glide slowly and silently, without any contortion. They seem to progress by some invisible power; but, if permitted to move over the bare hand, an experiment easily tried, a motion of the scales will be perceived. These are elevated and depressed, and act as levers, by which the animal is carried forward. Nor can a serpent progress with facility on the ground, without the resistance afforded by the scales. It is stated that it cannot pass over a plate of glass, or other entirely smooth surface. We saw the experiment tried, by

placing a small pane of glass in a box, in which was a common black snake. He was made to pass over it repeatedly, but evidently found that he had no foothold on it; and the third time, as he approached it, elevated the fore-part of his body slightly, and brought his head down beyond the glass, and, on passing, his body seemed scarcely to touch it. This gave an opportunity to witness the wave-like movement of the scales, that is, of their elevation, which runs from the head to the tail, enabling the animal to move continuously, instead of by a series of minute pushes, as would occur if all the scales be lifted and depressed at once.

In the moulting of the snake, which occurs yearly, and sometimes oftener, the outer covering of these creeping scales is shed; this is true also of the covering of the eyes, so that the cast epidermis represents, with great distinctness, the external features of the animal. In moulting, the outer skin is broken along the back, near the head, and the animal emerges, frequently drawing with him the skin, turning it inside out. Prof. Owen states, however, that in one instance exuviation commenced by the snake rubbing the skin loose around its jaws, working it back against the sides of its cage, when, putting its head through coils made by its own body, it pressed back the skin, turning it outward. We have observed that the black snake, on moulting, becomes more sensitive and irritable, but shy, and inclined, for a day or so, to keep close in a corner of his cage. The scaly covering of serpents must diminish their acuteness of touch; but we have found them sensitive to exceedingly slight irritation. They are without an external ear, and the phrase "deaf as an adder" is a familiar one. Nevertheless, they have organs of audition beneath the skin or protecting membrane, and we know by experiment that snakes hear and distinguish sounds, and are said in some instances to recognize the voice of their keeper. Some species, it has been observed, are influenced by music, and we quote the statement by Chateaubriand of an incident witnessed by himself. He says: "The Canadian began to play upon his flute. The snake (a rattlesnake) drew its head backward, its eyes lost their sharpness, the vibrations of its tail relaxed, and, turning its head toward the musician, remained in an attitude of pleased attention."

The snake-charmers (Fig. 3), familiar to travelers in Eastern countries, handle cobras with apparent impunity, cause them to advance or retreat, to coil and uncoil, to bow their heads, or bring their deadly mouths to their own by musical sounds, either vocal or instrumental. A story is related of an English gentleman, residing in a mountainous part of India, who was compelled to desist playing upon a flute because the music attracted serpents to his residence. The sense of taste in serpents must be very feeble, as it is quite unserviceable. They swallow their food whole, nor have they any teeth by which mastication can be accomplished. Their sense of smell is also obtuse. The

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