Page:Hardwicke's Science-Gossip - Volume 1.pdf/78

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
62
SCIENCE-GOSSIP.
[March 1, 1865.

FURTHER EXPERIENCES WITH TOADS.

My observations relate chiefly to the habits of the toad whilst feeding, and may be taken as a second chapter of E. D.'s very interesting paper (p. 12.)

My toads, two in number, had lived for a year or two in a hothouse which was devoted to the growth of pineapples. They were, I think, first placed there purposely by the gardener, who found them very useful in destroying insects. I used frequently to visit the place and amuse myself with feeding the toads with worms, and with watching their habits. The heat of the place, which was considerable, did not seem to inconvenience them in the least, for they were remarkably active, and of a large size; but at the same time they seemed greatly to enjoy the artificial showers when the plants were syringed, and would come out from their hiding-places to be rained upon. They usually remained amongst the pineapple plants, which grew on a bed raised some four feet from the ground, where they sat under the long leaves; but at the same time they seemed greatly to enjoy the artificial showers when the plants were syringed, and would come out from their hiding-places to be rained upon. They usually remained amongst the pineapple plants, which grew on a bed raised some four feet from the ground, where they sat under the long leaves; but when the place was watered they would not unfrequently jump down and lie upon the cool, wet tiles of the floor, spreading themselves out as flat as possible. How they climbed up to the pine-bed again I cannot say, for I never saw them do it.

They evinced very little shyness, taking worms readily when offered to them. When feeding, their actions were very curious. Upon placing a worm about three inches from a toad, it would instantly fix its attention upon it. Then its whole appearance was chaned. Instead of the dull, lethargic-looking animal that the toad generally appears, it was all vivacity; the body was instantly thrown somewhat back, and the head bent a little downwards, its bright eye riveted upon its prey; and though the toad was perfectly still as long as the worm remained motionless or nearly so, yet its attitude and its eager gaze were full of life and animation. Directly the worm made any active movement, the toad would dart forward, open its mouth from ear to ear, and seize it, generally about the middle. A curious scene now took place; mouth and feet went to work in good earnest; the worm was gulped down by a series of spasmodic jerks, trying to make its escape every time the mouth was opened, the toad thrusting it back all the time, and forcing it down its throat by the aid of its fore feet. Altogether it was rather a disgusting sight, and gave one the idea that the toad is an uncommonly greedy animal.

Having got the worm down was by no means a reason that it would stay there, for I have sometimes seen a worm rather larger than usual make its way up again; however, the feet would immediately go to work a second time, and the toad would at length remain the undisputed possessor of its own dinner.

Frequently I used to cheat the toads by moving a small twig before them. They would seize it directly, imagining it to be a worm, and would regard it with stupid astonishment when they discovered their mistake.

I never had the good fortune to see my friends take beetles or other small prey; but these the gardener told me were never seized with the mouth, but were caught with unerring aim upon the point of the long tongue.

I observe that toads will sometimes establish themselves inside a cucumber-frame, where no doubt they are very useful in destroying ants, spiders, and other small insects that would otherwise be very troublesome.

R. H.

SLUG OR SNAIL.

In answer to "W. Q. C."—What is the difference between a snail and a slug?

The most obvious distinction between a slug and a snail is, that the body of the former is elongated and naked, while in the latter it is more or less spiral, and covered by a more or less spiral shell.

The gasteropods, animals such as the garden snail, whelk, and slug, have a distinct foot placed under the body for crawling, and have a distinct head with tentacles, or, as they are commonly called, horns. They are divided into two great divisions—1stly, those which breathe by means of gills, as the whelk, and chiefly inhabit the sea—some, however, occur in our ponds and rivers; 2ndly, those which breathe by means of a lung, as the garden snail and pond snail, which latter, though living in the water, are obliged to come to the surface for the purpose of inhaling the air.

Now, in both these divisions are animals provided with shells, and others without them; to the first we give the name of snails, and the second we call slugs. And thus we have marine snails, as the whelk; slugs of the sea, as the sea hare; land and fresh-water snails, as the garden snail and pond shells; and land slugs, which, however, are more generally known as slugs.

With regard to the land snails and slugs, which are very similarly organized, there occur many connecting links, from the perfectly naked and elongate slug to the spirally-coiled garden-snail, capable of retiring within its shell. The land gasteropods of our own island furnish us with ample illustrations of forms intermediate between these two extremes. In the first place, there is the common black slug or land sole (Arion ater), without any shelly covering; then there naturally follows the spotted slug (Limax maximus) of our cellars and gardens, with the same slug-like body, but is provided with a rudimentary shell—where? Mark that oblong, shield-like elevation, immediately behind the head, as the animal is crawling; beneath that you may find a thin, shelly plate—this is the rudimentary shell. In a very remarkable slug (Testacellus haliotideus), a small ear-shaped. shell is placed externally at the hinder extremity of the animal. More markedly, there is the little green, glassy snail (Vitrina pellucida), so frequent in our woods amongst moss and decaying leaves, and rendered conspicuous by its green, glassy shell; it is intermediate in form between the slug and the snail, for it has the shield-like protuberance of the one and the spiral and external shell of the other; and further, some of the species of the genus (Vitrina) to which that, snail belongs cannot withdraw themselves into their shells.

R. T.

The Butterfly and the Nettle.—Watch the beauteous Vanessa Atalanta butterfly, lovely as the rose over which she flutters—see her sporting in the balmy air as if she had derived her origin from heaven, and was returning thither. But when she has to provide for her future progeny, does she deposit her eggs on the brilliant flowers where she spent her bridal? No! she retires to the nettles, and there safely leaves the infant embryo of a future race secure amidst the armature of the Urticæ. Thus a host of insects are sustained by an apparently useless weed, which is itself kept within due bounds by the caterpillars that feed upon it.—Edwin Lees.