FOOTNOTES:
[6] From a work entitled "Scenes of Italian Life," by L. Mariotti, just published in London.
A PLEA FOR BRITISH REPTILES.
What the flourishing tradesman writes with pride over his shop, we might in most cases write over our storehouse of antipathies—established in 1720, or 1751. For what good reason we, in 1851, should shudder at the contact of a spider, or loathe toads, it would be hard to say. Our forefathers in their ignorance did certainly traduce the characters of many innocent and interesting animals, and many of us now believe some portions of their scandal. To be a reptile, for example, is perhaps the greatest disgrace that can attach to any animal in our eyes. Reptile passes for about the worst name you can call a man. This is unjust—at any rate, in England. We have no thought of patting crocodiles under the chin, or of embracing boa constrictors; but for our English reptiles we claim good words and good-will. We beg to introduce here, formally, our unappreciated friends to any of our human friends who may not yet have cultivated their acquaintance.
The Common Lizard—surely you know the Common Lizard, if not by his name of state—Zootoca vivipara. He wears a brilliant jacket, and you have made friends with him, as a nimble, graceful fellow; as a bit of midsummer. His very name reminds you of a warm bank in the country, and a sunny day. Is he a reptile? Certainly; suppose we stop two minutes to remember what a reptile is.
The heart of a reptile has three cavities; that is to say, it is not completely double, like our own. It sends only a small part of the blood which comes into it for renovation into the air-chambers—the lungs; while the remainder circulates again unpurified. That change made in the blood by contact with the oxygen of air, is chiefly the cause of heat in animals. Aëration, therefore, being in reptiles very partial, the amount of heat evolved is small; reptiles are therefore called cold-blooded. They are unable to raise their heat above the temperature of the surrounding air. Fishes are cold-blooded, through deficient aëration in another way; in them, all the blood passes from the heart into the place where air shall come in contact with it; but, then there is a limitation to the store of air supplied, which can be no more than the quantity extracted from the water. The temperature of water is maintained below the surface, and we know how that of the air varies, since a certain quantity of heat is necessary to the vital processes; reptiles, depending upon air for heat, hybernate or become torpid when the temperature falls below a certain point. The rapidity of all their vital actions will depend upon the state of the thermometer; they digest faster in the heat of summer than in the milder warmth of spring. Their secretions (as the poison of the adder) are in hot weather more copious, and in winter are not formed at all. The reptiles breathe, in all cases, by lungs; but we must except here those called Batrachians, as frogs or newts, which breathe, in the first stage, by gills, and afterward by gills and lungs, or by lungs only. The Batrachians, again, are the only exception to another great characteristic of the reptile class, the hard, dry covering of plates or scales. The reptiles all produce their young from eggs, or are "oviparous"—some hatch their eggs within the body, and produce their young alive, or are "ovo-viviparous." These are the characters belonging to all members of the reptile-class. The class is subdivided into orders somewhat thus: 1. The Testudinate (tortoises and turtles). 2. Enaliosaurian (all fossil, the Ichthyosaurus and his like). 3. Loricate (crocodiles and alligators). 4. Saurian (lizards). 5. Ophidian (serpents); and the last order, Batrachian (frogs, toads, &c.); which is, by some, parted from the reptiles, and established as another class.
Now we have in England no tortoises or turtles, and no crocodiles: and the fossil order is, in all places, extinct; so our reptiles can belong only to the three last-named orders, Lizards, Serpents, and Batrachians.
Thus we come back, then, to our Lizards, of which we have among us but two genera, a single species of each. These are the Common Lizard, well known to us all, and the Sand Lizard, known only to some of us who happen to live upon the southern coast. The species of lizard so extremely common in this country, has not been found in countries farther south, and is, in fact, peculiar to our latitude. We, therefore, may love him as a sympathetic friend. The sand lizard (Lacerta agilis) is found as far north as the country of Linnæus, and as far south as the northern part of France; in England, however, it seems to be rare, and has been detected only in Dorsetshire—chiefly near Poole, or in some other southern counties. It frequents sandy heaths, and is of a brown sandy color, marked and dotted; but there is a green variety said to be found among the verdure of marshy places. It is larger than our common lizard, averaging seven inches long, is very timid, and when made a prisoner pines and dies. Its female lays eggs, like a turtle, in the sand, covers them over, and leaves them to be hatched by the summer sun. This kind of lizard, therefore, is oviparous. The eggs of our common lizard are hatched also by the sun; for, reptiles having no heat of their own, can not provide that which is necessary to the development of an embryo; but in this case the sun hatches them within the parent's body. The female of this lizard stretches herself out upon a sunny bank, and lets the bright rays fall upon her body while she lies inactive. At this period, she will not move for any thing less than a real cause of alarm. She is not sunning herself lazily, however, but fulfilling an ordinance of God. The eggs break as the young lizards—three to six—are born. This lizard is, therefore, ovo-viviparous. The little ones begin at once to run about, and soon dart after insects, their proper food; but they accompany the mother with some instinct of affection for a little time. These lizards are very various in size and color; difference in these respects does not denote difference in kind. The little scales which cover them are arranged in a peculiar manner on the head, under the neck, &c.; and some differences of arrangement, in such respects, are characteristic. The best distinction between the only two species of lizard known in this country has been pointed out by Mr. Bell. In the hind legs, under each thigh, there is a row of openings, each opening upon a single scale. In sand lizards, the opening is obviously smaller than the scale; in our common lizards, the opening is so comparatively large that the scale seems to be the mere edge of a tube around it.
These are our lizards, then, our Saurian reptiles; and they do not merit any hate. Suffer an introduction now to English Snakes.
The first snake, the Blindworm, is not a snake, nor yet a worm. It is a half-way animal—between a lizard and a snake. The lizards shade off so insensibly into the snakes, even the boa preserving rudimentary hind legs, that some naturalists counsel their union into a single class of Squamate, or scaled reptiles. By a milder process of arrangement, all those animals which dwell upon the frontier ground between Lizards or Saurians, and Ophidians or Snakes, are to be called Saurophidian. The blindworm then, is Saurophidian; it is quite as much a lizard as a snake. Snakes have the bones of their head all movable, so that their jaws can be dilated, until, like carpet-bags, they swallow any thing. The lizard has its jaws fixed; so has the blindworm. Snakes have a long tongue, split for some distance, and made double-forked; the blindworm's tongue has nothing but a little notch upon the tip. It has a smooth round muzzle, with which it can easily wind its way under dry soil to hybernate; or else it takes a winter nap in any large heap of dead leaves. It comes out early in the spring; for it can bear more cold than reptiles generally like, and it is found all over Europe, from Sweden to the south of Italy. It feeds upon worms, slugs, and insects. Like the snakes, it gets a new coat as it grows, and takes the old one off, by hooking it to some fixed point, and crawling from it, so that the cast skin is dragged backward, and turned inside out. The slow-worm is of a dark gray color, silvery, and about a foot long on the average. It is ovo-viviparous. It is extremely gentle; very rarely thinks of biting those who handle it, and, when it does bite, inflicts no wound with its little teeth. Of course it has no fangs and is not poisonous. Shrinking with fear when taken, it contracts its body and so stiffens it that it will break if we strike or bend it. Therefore it bears the name Linnæus gave it—Anguis fragilis.
We have found nothing yet to shudder at among our reptiles. "O! but," you say perhaps, "that was not a real snake." Well, here is our real snake. Natrix torquata—our common Ringed Snake; he is very common. He may be three or four feet long, and brownish-gray above, with a green tinge, yellow marks upon the neck, and rows of black spots down the back and sides, alternating, like London lamp-posts, with each other. You will find him any where in England, almost any where in Europe, below the latitude of Scotland. You will find him most frequently in a moist place, or near water, for he is rather proud of himself as a swimmer. He has a handsome coat, and gets a new one two, three, four, or five times in a season, if his growth require it. When the new coat is quite hard and fit for use under the old, he strips the old one off among the thorn-bushes. He and his lady hybernate. The lady leaves her sixteen or twenty eggs, all glued together, for the sun to vivify. The snake's tongue, as we have said, is forked, the jaws dilatable; he prefers frogs for his dinner, but is satisfied with mice, or little birds, or lizards. He swallows his prey whole. Catching it first, as Mrs. Glasse would say, between his teeth, which are in double rows upon each jaw, and directed backward that they may act more effectually, he first brings the victim to a suitable position—head first he prefers, then, leaving one set of teeth, say the lower, fixed, he advances the upper jaw, fixes its teeth into the skin, and leaves them there while he moves forward, the lower jaw, and so continues till the bird or frog is worked into his throat; it is then swallowed by the agency of other muscles. This power of moving each jaw freely and in independence of the other, is peculiar to Ophidian reptiles. The frog may reach the stomach both alive and active, so that, if afterward, the snake gapes, as he is apt to do, a frog has been seen to leap out again. The processes of life are so slow in reptiles, that one meal will not be digested by the snake for many days. He is unable to digest vegetable matter. Our snake is very harmless, and if kept and fed, will quickly learn to recognize its patron, will feed out of his hand, and nestle up his sleeve; but he shows a dread of strangers.
We have Adders? Yes, we have a Viper—Pelias Berus is the name he goes by, and his fangs are undeniable. This is the only native reptile that can, in any degree whatever, hurt a man. It is common in England, and, unlike the snake, prefers a dry place to a moist one. "Adder" and "viper" are two words applied to the same thing—adder being derived from the Saxon word for "nether," and viper from viviper; because this reptile, like our common lizard, hatches her eggs within the body, or is viviparous. Our viper is found all over Europe; not in Ireland. As for Ireland, it is an old boast with the Irish that Saint Patrick banned away all reptiles. The paucity of reptiles in Ireland is remarkable, but they are not altogether absent. Our common lizard has a large Irish connection, and frogs were introduced into Ireland years ago. Their spawn was taken over, put into water, throve, and thereafter frogs have multiplied. An attempt was also made to introduce our common snake, but the country-people, with great horror, killed the inlopers; a reward even was offered for one that was known to remain uncaptured. Ireland is free from adders.
The most ready distinction between a common snake and an adder, to unfamiliar eyes, is founded on the difference of marking. While the snake has separate alternate spots, the adder has, down its back, a chain of dark spots, irregularly square, and joined to one another. Adders are generally brown, but differ very much in color. They have on their upper jaw, instead of their lower, a row of teeth, the well-known fangs. These are long, curved teeth, fixed into a movable piece of bone, and hollow. The hollow is not made out of the substance of the tooth; it is as if a broad flat tooth had been bent round upon itself to form a tube. The tube is open below and behind, in the curve, by a little slit. Above, it is open, and rests upon a tiny bag connected with a gland that corresponds to a gland in man for the secretion of saliva; but which, in the present case, secretes a poison. The fang, when out of use, is bent and hidden in a fleshy case; in feeding, it is rarely used. The viper catches for himself his birds or mice, after the manner of a harmless serpent. But, when hurt or angered, he throws back his neck, drops his fang ready for service, bites, and withdraws his head immediately. The fang in penetrating, of necessity, was pressed upon the little bag of poison at its root, and forced a drop along the tube into the wound. After a few bites, the bag becomes exhausted, and the adder must wait for a fresh secretion. The poison has no taste or smell, and may be swallowed with impunity, if there be no raw surface in the mouth, or sore upon the throat, or in the stomach. It is only through a wound that it can act like poison. The bite of an adder in this country never yet proved fatal; but, according to the health of the person bitten, and according to the greater or less heat of the weather (for in very hot weather a more active poison is secreted), the wound made will be more or less severe. It is advisable to get out of an adder's way.
All the remaining reptiles in this country are two species of Frog, two species of Toad, and four Newts. They are not only most absolutely harmless, but, the frogs, at any rate, and toads, are ministers to man; and they belong to a class of animals more interesting than any other, perhaps, in the whole range of natural history. We are all well acquainted with the common frog, whose grander name is Rana temporaria. We see it—and it is to be feared some of us kill it—in our gardens, among strawberry-beds and damp vegetation. But, whereas frogs feed upon those slugs and insects which are in the habit of pasturing upon our plants, and are themselves indebted to us for not a grain of vegetable matter, we ought by all means to be grateful to them. So industrious are frogs in slug-hunting, that it would be quite worth while to introduce them as sub-gardeners upon our flower-beds. In catching insects, the frog suddenly darts out his tongue, which, at the hinder part, is loose, and covered with a gummy matter. The insect is caught, and the tongue returned with wonderful rapidity. The frog, when it is first hatched, has the constitution of a fish: it is purely aquatic; has a fish's heart, a fish's circulation, and a fish's gills. The tadpole swims as a fish does—by the movement, side-ways, of its tail. For the unassisted eye, and still more for the microscope, what spectacle can be more marvelous than the gradual process of change by which this tiny fish becomes a reptile? Legs bud; the fish-like gills dwindle by a vital process of absorption; the fish-like air-bladder becomes transmuted, as by a miracle, into the celled structure of lungs; the tail grows daily shorter, not broken off, but absorbed; the heart adds to its cells; the fish becomes a reptile as the tadpole changes to a frog. The same process we observe in toads; and it is also the same in our newts, excepting that in newts the tail remains. There is no parallel in nature to this marvelous and instructive metamorphosis.
The perfectly-formed frog does not live of necessity in water, or near it, but requires damp air occasionally. It breathes by lungs, as we have said; but, as it has no ribs, there is no chest to heave mechanically. The frog's air has to be swallowed, to be gulped down into the lungs. That is not possible unless the mouth is shut; and, therefore, as we might suffocate a man by keeping his mouth shut, so we should suffocate a frog by keeping his mouth open. Yet we should not suffocate him instantly; we should disable the lungs; but, in this class of animals the whole skin is a breathing surface. A frog has lived a month after his lungs had been extracted. All respiratory surfaces, like the inside of our own lungs, can act only when they are relaxed and moist. That is the reason why a frog's skin is always moist, and why a frog requires moist air. It does not need this constantly, because, when moisture is abundant, there is a bag in which it stores up superfluity of water, to be used in any day of need. It is this water—pure and clear—which frogs or toads expel when they are alarmed by being handled. Is not enough said here, to rescue frogs from our contempt? We may add, that they are capable of understanding kindness—can be tamed. Frogs hybernate under the mud of ponds, where they lie close together, in a stratum, till the spring awakens them to a renewal of their lives and loves. They lay a vast number of eggs, at the bottom of the water; and the multitudes of young frogs that swarm upon the shore when their transformation is; complete, has given rise to many legends of a shower of frogs. These multitudes provide food for many animals, serpents, as we have seen, birds, fish. And the survivors are our friends.
The other species of frog found in this country is the Edible Frog (Rana esculenta). It has for a long time had a colony in Foulmire Fen, in Cambridgeshire, although properly belonging to a continental race. It differs from our common frog in wanting a dark mark that runs from eye to shoulder, and in having, instead of it, a light mark—a streak—from head to tail along the centre of the back. The male is a more portentous croaker than our own familiar musicians, by virtue of an air-bladder on each cheek, into which air is forced, and in which it vibrates powerfully during the act of croaking. This kind of frog is always in or near the water, and being very timid, plunges out of sight if any one approaches.
These are our frogs; as for our two Toads, they are by no means less innocent. They are the Common Toad, by style and title Bufo vulgaris, and a variety of the Natter Jack Toad, to be found on Blackheath, and in many places about London, and elsewhere. The toad undergoes transformations like the frog. It is slower in its movements, and less handsome in appearance: similar in structure. There is a somewhat unpleasant secretion from its skin, a product of respiration. There is nothing about it in the faintest degree poisonous. It is remarkably sensible of kindness; more so than the frog. Examples of tame toads are not uncommon. Stories are told of the discovery of toads alive, in blocks of marble, where no air could be; but, there has been difficulty, hitherto, in finding one such example free from the possibility of error. It may be found, however, that toads can remain for a series of years torpid. It has been proved that snails, after apparent death of fifteen years, have become active on applying moisture. A proof equally distinct is at present wanting in the case of toads. The toad, like other reptiles, will occasionally cast its skin. The old skin splits along the back, and gradually parts, until it comes off on each side, with a little muscular exertion on the toad's part. Then, having rolled his jacket up into a ball, he eats it!
No reptiles remain now to be mentioned, but four species of Newt. These little creatures are abundant in our ponds and ditches, and some are most falsely accused of being poisonous. They are utterly harmless. Their transformations, their habits, their changes of skin, their laying of eggs, can easily be watched by any who will keep them in a miniature pond. A large pan of water, with sand and stones at the bottom, decayed vegetable matter for food, and a few living water-plants, extracted from their native place, will keep a dozen newts in comfort. The water-plants are needed, because a newt prefers to lay her egg upon a leaf. She stands upon it, curls it up with her hind legs, and puts an egg between the fold, where it remains glued. These being our reptiles, are they proper objects of abhorrence? At this season they are all finishing their winter nap. In a few weeks they will come among us, and then, when
"the songs, the stirring air,
The life re-orient out of dust,
Cry through the sense to hearten trust
In that which made the world so fair"—
may we not permit our hearts to be admonished by the reptiles also?