ham, in Ray's Wisdom of God in the Creation (p. 365), concerning the migration of frogs from their breeding ponds*. In this account he at once subverts that foolish opinion of their dropping from the clouds in rain; showing that it is from the grateful coolness and moisture of those showers that they are tempted to set out on their travels, which they defer till those fall. Frogs are as yet in their tadpole state; but, in a few weeks, our lanes, paths, fields will swarm for a few days with myriads of those emigrants, no larger than my little finger nail. Swammerdam gives a most ac

and putting him down in the midst of it. He would raise himself on all fours, and with his eyes glistening with something like civic ecstasy, would dart out his tongue, right and left, as rapidly as lightning, and lap up the ants in quick succession, with the most laughable gulosity. I also gave him earwigs, glowworms, woodlice, grasshoppers, spiders, dragon-flies, ticks, horse-leeches, grubs, moths, and any insect I could meet with. All seemed equally welcome, either by night or by day; but it was most diverting to see him contend with a worm. He would dart upon it, secure one end, and swallow with all his might; but the worm would annoy him by creeping out of his mouth before he could swallow it entirely; and I have known him persevere for nearly half an hour, attempting to secure his prize, while the worm kept constantly escaping. He would take a snail, when he once saw it extended and in motion; though he always dashed at the shell, and took all down together in a moment, but could not manage one of large size. It was to me a great source of amusement to feed him and watch his singular movements. He was often frightened, but seldom provoked. I once or twice, however, provoked him, I think, to as much wrath as his cold nature was susceptible of; but I feel quite assured that the toad is at all times perfectly harmless and inoffensive: the idea of its spitting, or otherwise discharging venom is, I am convinced, wholly unfounded. In the winter months my toad always refused food, though he did not become torpid, but grew thin, and moved much less than at other times. He did not eat from the end of November till March, gradually losing his appetite and gradually recovering it: he never seemed affected by cold, except in the way of losing his inclination for food."-RENNIE.

4 Concerning the reason of frogs coming out in rainy weather, the reader will be amply gratified, by referring to the experiments made by Dr. Townson on his two frogs, Damon and Musidora. See his Tracts, p. 50. The general result of which has proved the following curious fact: "that frogs take in their supply of liquid through the skin alone, all the aqueous fluid which they take in being absorbed by the skin, and all they reject being transpired through it. One frog in an hour and a half absorbed nearly its own weight of water."-Mitford.

curate account of the method and situation in which the male impregnates the spawn of the female. How wonderful is the economy of Providence with regard to the limbs of so vile a reptile! While it is an aquatic it has a fish-like tail, and no legs: as soon as the legs sprout, the tail drops off as useless, and the animal betakes itself to the land5!

Merret, I trust, is widely mistaken when he advances that the Rana arborea is an English reptile; it abounds in Germany and Switzerland'.

It is to be remembered that the Salamandra aquatica of Ray (the water-newt or eft) will frequently bite at

The whole of the typical Batrachia, the frogs, toads, newts, salamanders, &c. undergo a complete metamorphosis. In the land species, as from their habits they have not constant access to water, the aquatic portion of their existence, during which the gills remain attached, cannot be passed in that medium in the same manner as the frogs, &c. They undergo the metamorphosis therefore in the oviduct, before they are excluded from the mother, and come forth in the perfect condition. But in the other forms, the change takes place in the water, and the young live there for a time in a fish-like state, as regards not only their respiration, but most of the other functions of life. There is, however, another deviation from this rule, still more remarkable than that of the salamander, in the pipa or Surinam toad; in which the male places the eggs on the back of the female, impregnates them, and leaves them attached by a very glutinous mucus. The skin of the mother grows up around the eggs, forming a cell for each, in which the young leave the egg, and undergo their metamorphosis.

The common water newt or eft exhibits a beautiful example of this interesting change, retaining its pretty reddish leaf-like gills till the animals are an inch or more in length.-T. B.

* [Hyla viridis, LAUR.]

7 From the way in which Mr. White speaks of the tree frog, it might be inferred that he thought it was possessed of injurious qualities, whereas a more innocent creature does not exist; and it is besides so little, and of so beautiful a green, that it is a very common pet in Germany. My friend, J. C. Loudon, Esq. the well known author of the Encyclopædia of Gardening, kept one for several years; and in the autumn of 1830, I caught one sitting on a bramble at Cape La Héve, on the coast of Normandy, which I kept for many weeks; but it finally escaped from me between Bayswater and Hyde Park Corner, by the gauze covering of its glass accidentally slipping off before I was aware. -RENNIE.

the angler's bait, and is often caught on his hook. I used to take it for granted that the Salamandra aquatica was hatched, lived, and died, in the water. But John Ellis, Esq., F. R. S., (the coralline Ellis), asserts, in a letter to the Royal Society, dated June the 5th, 1766, in his account of the mud inguana, an amphibious bipes from South Carolina, that the water-eft, or newt, is only the larva of the land-eft, as tadpoles are of frogs. Lest I should be suspected to misunderstand his meaning, I shall give it in his own words. Speaking of the opercula, or coverings to the gills, of the mud inguana, he proceeds to say that "The form of these pennated coverings approaches very near to what I have some time ago observed in the larva, or aquatic state, of our English Lacerta, known by the name of eft, or newt; which serve them for coverings to their gills, and for fins to swim with while in this state; and which they lose, as well as the fins of their tails, when they change their state and become land animals, as I have observed, by keeping them alive for some time myself."

Linnæus, in his Systema Naturæ, hints at what Mr. Ellis advances, more than once.

Providence has been so indulgent to us as to allow of but one venomous reptile of the serpent kind in these kingdoms, and that is the viper. As you propose the good of mankind to be an object of your publications, you will not omit to mention common salad-oil as a sovereign remedy against the bite of the viper3.

The efficacy of oil as a remedy against the bite of the viper has probably been overrated. It is generally believed in those parts of the country where vipers abound to be very efficacious as an external application, as is also the fat of the reptile itself. The exhibition of ammonia both as an external and internal remedy, is recommended probably on surer grounds. I never heard of a well authenticated instance of the bite of the English viper proving fatal, though I have known and seen several cases in which the symptoms appeared to be extremely dangerous. -T. B.

As to the blind worm (Anguis fragilis, so called because it snaps in sunder with a small blow), I have found, on examination, that it is perfectly innocuous9.

A neighbouring yeoman (to whom I am indebted for some good hints) killed and opened a female viper about the 27th of May: he found her filled with a chain of eleven eggs, about the size of those of a blackbird; but none of them were advanced so far towards a state of maturity as to contain any rudiments of young. Though they are oviparous, yet they are viviparous also, hatching their young within their bellies, and then bringing them forth. Whereas snakes lay chains of eggs every summer in my melon beds, in spite of all that my people can do to prevent them; which eggs do not hatch till the spring following, as I have often experienced. Several intelligent folks assure me that they have seen the viper open her mouth and admit her

9 A blind-worm, that I kept alive for nine weeks, would, when touched, turn and bite, although not very sharply: its bite was not sufficient to draw blood, but it always retained its hold until released. It drank sparingly of milk, raising the head when drinking. It fed upon the little white slug (Limax agrestis, LINN.) so common in fields and gardens, eating six or seven of them one after the other; but it did not eat every day. It invariably took them in one position. Elevating its head slowly above its victim, it would suddenly seize the slug by the middle, in the same manner that a ferret or dog will generally take a rat by the loins; it would then hold it thus sometimes for more than a minute, when it would pass its prey through its jaws, and swallow the slug head foremost. It refused the larger slugs, and would not touch either young frogs or mice. Snakes kept in the same cage took both frogs and mice. The blind-worm avoided the water: the snakes, on the contrary, coiled themselves in the pan containing water, which was put into the cage, and appeared to delight in it. The blind-worm was a remarkably fine one, measuring fifteen inches in length. It cast its slough while in my keeping. The skin came off in separate pieces, the largest of which was two inches in length; splitting first on the belly, and the peeling from the head being completed the last. After the skin was cast the colour of the reptile was much lighter than it had before been.

I had for the first time, while this blind-worm was in my custody, an opportunity of witnessing the power which slugs have of suspending themselves by a thread. They availed themselves of it in escaping from the cage of the reptile. The cage was on a shelf four feet six inches from the floor, and, with the aid of the glutinous filament which they exuded, the slugs lowered themselves from it to the ground.-G. D.

helpless young down her throat on sudden surprises, just as the female opossum does her brood into the pouch under her belly, upon the like emergencies; and yet the London viper-catchers insist on it, to Mr. Barrington, that no such thing ever happens 1o. The serpent kind eat, I believe, but once in a year; or, rather, but only just at one season of the year11. Country people talk much of a water-snake, but, I am pretty sure, without any reason; for the common snake (Coluber Natrix) delights much to sport in the water, perhaps with a view to procure frogs and other food.

I cannot well guess how you are to make out your twelve species of reptiles, unless it be by the various species, or rather varieties, of our Lacertæ, of which Ray enumerates five. I have not had opportunity of ascertaining these; but remember well to have seen, formerly, several beautiful green Lacerta on the sunny sandbanks near Farnham, in Surrey 12; and Ray admits there are such in Ireland.

10 I have been assured by a very honest and worthy gardener in Dorsetshire, that he had seen the young vipers enter the mouth of the mother when alarmed. I have never been able to obtain further evidence of the fact, though I have made the most extensive inquiries in my power. If it be untrue, the popular error may have arisen from the circumstance of fully formed young having been found in the abdomen of the mother, ready to be excluded. The actions of the young which were emancipated from the oviduct by White on a subsequent occasion (see Letter XXXI. to Daines Barrington) do not appear necessarily to bear upon the question, as there are many instances of the young of animals manifesting the habits and instincts of their species immediately on coming into the world -as in the case of young ducks seeking the water, &c.-T. B.

The slow power of digestion possessed by serpents renders them capable of remaining long without food. If a snake swallows a frog, or a viper a mouse, it is several weeks before it is digested. It is probable, accordingly, that they do not eat above three or four times in the course of a summer, and in winter not at all. During the summer of 1830, I kept both a slow worm (Anguis fragilis) and a snake (Coluber Natrix) for several months, during which time they refused every sort of food I could offer them. When taken in the autumn, M. Bory St. Vincent says they will endure abstinence for an incredible period; but this will not be the case if they are taken in spring.-Rennie.

12 [See Letter XXII.]