Snakes: Curiosities and Wonders of Serpent Life

by Catherine Cooper Hopley

This working of the jaws would be almost imperceptible excepting to a very close observer. In the lower jaw-bones the independent action can be more readily perceived and is often very grotesque, one side of the mouth opening while the other is closed, conveying the idea of the reptile making grimaces at you; but the gradual disappearance of the prey so much more bulky than the snake itself is quite incomprehensible until we are acquainted with the remarkable phenomena of the six rows of teeth acting independently. Thus, in turning the frog round to adjust it to a more convenient position, the jaws acted like hands in moving, dragging, or shifting some cumbrous article, say a carpet or a plank, when the left hand follows the movement of the right hand until the plank or carpet is worked round or forward in the required direction.

The form and arrangement of the fine claw-shaped teeth assist the process. They are too close together, and the pressure is too slight to inflict a wound; they merely retain what they hold, and it is in vain for the prey to struggle against them, or it might get some ugly scratches as they all incline backwards. In chapter xix. illustrations of teeth, life-size, show their forms and direction; here it only need be added regarding them, that the above description refers chiefly to the non-venomous snakes.

The palate being covered with that armoury of teeth, the snake must have but a slight sense of taste, which is to its advantage, we should say; for having no assistant in the shape of beak or limbs to divide its prey, hair, fur, feathers, dust—all must be swallowed with the meal, completely disguising whatever flesh they cover, so that we should suppose the process of feeding could be productive of very little enjoyment to the reptile. Perhaps out of this state of things has developed their habit of eating so seldom, but when they do take the trouble of feeding, of doing it thoroughly, so that their meal lasts them a long while.

Deglutition is greatly facilitated by an abundant supply of saliva, which lubricates that uncomfortable coating of feathers or fur; but ‘lubrication’ is understood to refer merely to the natural secretions of the mouth, in which the tongue performs no part at all.

The salivary apparatus of snakes is peculiar to them, and very complicated. Even the nasal and lachrymal glands pour their superfluous secretions through small canals into the mouth.[4] These active and abundant glands are excited by hunger or the sight of food, just as in mammals; and for the more common expression of the mouth ‘watering’ that of ‘lubrication’ is here used, because over the rough-coated prey these salivary secretions act as a great aid in deglutition. The erroneous impressions that have obtained on this subject are touched upon in describing the tongue (chap. vi.).

A circumstance happened at the London Zoological Gardens a few years ago, which, although familiar to many, may be referred to as bearing on two of the above features—namely, the dull sense of taste in a snake, and the abundant supply of mucous secretions. It was in the case of a large boa which swallowed her blanket. She was about to change her skin, and, as usual on such occasions, was partially blind, as also indifferent to food. The rabbits given to her dodged her grasp, and her appreciation of flavours was not sufficient to enable her to discriminate between blanket and rabbit fur; so, seizing a portion of the rug, she with natural instinct constricted this, and proceeded to swallow it. She was, however, made to disgorge it afterwards, when it was scarcely recognisable from the thick and abundant coating of mucous in which it was enveloped. Mr. F. Buckland described its appearance as that of a ‘long flannel sausage.’

These highly-developed salivary glands are beneficent provisions in the economy of the serpent race. The reptile cannot, as we said, tear flesh from bones, and discard the latter; nor separate the food from the enveloping feathers or fur; nor reject whatever unsavoury portions other animals might detach and leave uneaten. All must be swallowed by a snake, and all digested; and its digestion, sufficiently powerful, is aided by the excessive flow of saliva, or the insalivation of such food.

It is not difficult to make snakes disgorge their food. They often do so on their own account, when, after swallowing some bulky meal, they are alarmed or pursued, and escape is less easy with that load to carry. The illustration exhibiting the numerous ribs, which are all loosely articulated with the spinal column, enables us to comprehend the capacity for bulk, and the ease with which these fine ribs would expand to accommodate a body even broader than the snake itself. We comprehend, also, why it is that a creature swallowed alive need not be injured or wounded by the mere fact of being swallowed, but would die of suffocation after all. A frog has been known to turn round and escape from the body of the snake, if the latter indulge in a prolonged yawn; and yawning almost always does follow as soon as the prey is swallowed, because the snake has for the time breathed less regularly, and now requires to take in a fresh supply of air. In this act you see the two jaws extended to an enormous degree, almost, indeed, to form one straight line perpendicularly. In such condition the teeth are well out of the way, and the adjustable ribs, expansile covering, and loose head bones render them not insurmountable obstacles to an escape when the prey is uninjured.

One sometimes hears of the egg-stealing snakes, cobras, etc., when surprised and pursued, first relieving themselves of their plunder before they attempt to escape. Often it may be observed, when two snakes are in a cage together, and both get hold of the same frog or rat, that they each advance upon it till their heads meet, when either the stronger or the larger snake will gain the day, and finish his frog, and then proceed to swallow his friend; or else one will relinquish his hold, when, even in those few minutes, the half-swallowed prey will be completely disguised in the mucous saliva which has already enveloped it.

Some snakes, though not quarrelsome at other times, for some reason inexplicable to the looker-on, persistently set their heart on the same bird or frog, though many are presented for their choice. In a pair of Tropidonoti at the Gardens this occurs almost every week; and in such instances the keeper keeps a sharp watch over them; for as neither snake will relinquish its capture, the one that begins first comes in contact with the head of his comrade, who will assuredly be swallowed too, were not a little moral, or rather physical coercion in the shape of a good shaking administered. Sometimes both get their ears boxed, figuratively; yet the discipline has no more than a passing effect, and next week the same thing happens again.