Snakes: Curiosities and Wonders of Serpent Life

by Catherine Cooper Hopley

Though in form the ‘neck’ of a snake is often as undistinguishable as the tail—‘une tête sans col, et une queue, dont l’origine se confond avec le reste du corps,’ as Dumeril expresses it—there is the one invariable rule belonging to it, namely, that the first two joints of a snake’s spine are ribless, and that the ribs begin at the third. Physiologists tell us a snake has no neck, and for reasons which will be explained in the next chapter; yet, by way of distinction, all speak of ‘the neck’ as an accepted fact.

No invariable rule as to tails can, however, be established, either as regards length, shape, or character. Firstly, the length of the tail varies from inches to feet in snakes of nearly the same size. Secondly, both venomous and harmless ones are occasionally furnished with horny tips, and both vibrate them with equal rapidity. Thirdly, snakes that have long spineless tails also vibrate them rapidly; as do snakes with short spineless tails; so that one cannot say that spines are confined to one genus, any more than is their use or their action. The vibration of the tail is, in fact, only ‘an outlet for suppressed energy,’ as Professor Shaler of the United States has lucidly put it. Excitement displays itself in the tail of a snake as much as in the tail of a dog. This may be observed at the Ophidarium, or wherever an active snake can be watched. In the rattlesnake it is, of course, more conspicuous, and always audible when agitated; but many others similarly display their feelings in their eloquent caudal terminations.

A handsome young python, of about eight feet long, at the Zoological Gardens, has a tail of which the last few inches taper so suddenly that the extreme end of this reptile appears almost ludicrously trivial for so fine a possessor. One inch of this—hardly thicker than a rat’s tail—you may see wriggling so rapidly that you can scarcely follow its movements, or believe that it is a part of the large quiescent body to which it is attached. In pursuit of its prey the python itself glides with slow dignity, while the trifling little terminal inch or so of tail is in a perpetual but most undignified wriggle.

In the ‘Racer,’ already familiar to the reader, the tail is one-fourth the length of the body; in the ‘milk snake’ (Coluber eximius), introduced in chapter iv., it is one-fifth. The extensive variation in tails may be comprehended by their number of vertebræ, which in some snakes amount to 200, and in others are reduced to 5.

Of the practical uses of the snake’s tail, the natural uses,—those above mentioned being either imaginary ones, or a mere expression of feeling,—the prehensile power is one of the greatest. ‘Strictly speaking, the true prehensile tail is found only in the boa,’ Schlegel, Owen, and other physiologists tell us; but that statement refers to some peculiar anatomical construction, enabling the tail to twine and grasp with extraordinary force, because nearly all snakes can manage to climb, or to raise themselves when occasion requires it, making use of their tails, as was stated at the commencement of this chapter. ‘Even the clumsy, ugly death adder can climb well,’ Krefft assures us, and that it can support itself against a wall with only a portion of its tail on the ground.

Many writers and observers, in describing this power or force in the snake, have given rise to the idea that snakes can stand on their tails. Erect themselves nearly upright they certainly do, even without extraneous support for a few moments, and with support for a considerable time.

Cobras can do this. A personal friend, Colonel C——, when in India, once heard a sort of muffled sound at his door, which caused him to open it suddenly, when a cobra, which had raised itself three or more feet against it, fell straight into the room. He sprang quickly aside, and ran to fetch a stick, but when he got back the cobra was gone.

But to return to their prehensile powers. Snakes which are not habitual climbers are often found in trees, suspending themselves from or supporting themselves upon the branches, as instanced in the chapter on the egg-eaters. The Hamadryad is also much in trees, as its name implies, and is seen hanging from the branches. This latter, and also the Indian tree snakes, Trimeresuri, are poisonous, and far removed from the boas with the true prehensile tail. Familiar to every one are illustrations of tropical scenery, in which the boa constrictor and the anaconda, hanging from trees, are important features. Dumeril, in general terms, says: ‘Les ophidiens rampent, glissent, s’accrochent, se suspendent, gravissent en s’aidant de la totalité de leur corps, sautent, s’élancent, bondissent, nagent, et plongent,’[56] in every one of which movements the tail is an important agent. S’accrocher and se suspendre must be mainly by the agency of the tail. Schlegel follows up his statement, ‘tail strictly prehensile found only in boas,’ by explaining, nevertheless, that a short tail is sufficiently vigorous to attach itself to any point, and support the whole body.[57] In the non-venomous tree snakes the tail is long and slender, and no squirrel or bird is more active and at home in a tree than these. They glide, swing, climb, and almost fly from branch to branch, scarcely disturbing a leaf.

Our ‘excellent egg merchant,’ introduced as the Racer, though a ground snake, is equally at home in a tree, and holds on by its tail with remarkable adroitness, but then the Racer or ‘Pilot snake’ is a true boa also. (The true ‘boa’ is distinguished by its dentition and formation of jaw-bones, the term ‘boa,’ so variously and perplexingly used by some of the older naturalists, being now restricted to certain non-venomous species which possess such anatomical structure.)