their holes, but keep the ends of their tails fixed therein, so that on the least alarm they can retire with precipitation under the earth. Whatever food falls within their reach when thus extended they seem to be content with—such as blades of grass, straws, fallen leaves, the ends of which they often draw into their holes; even in copulation their hinder parts never quit their holes; so that no two, except they lie within reach of each other's bodies, can have any commerce of that kind; but as every individual is an hermaphrodite, there is no difficulty in meeting with a mate, as would be the case were they of different sexes.-WHITE

SNAILS AND SLUGS.

The shell-less snails called slugs are in motion all the winter in mild weather, and commit great depredations on garden plants, and much injure the green wheat, the loss of which is imputed to earth-worms; while the shelled snail, the pepeokos, does not come forth at all till about April 10th, and not only lays itself up pretty early in autumn, in places secure from frost, but also throws out round the mouth of its shell a thick operculum formed from its own saliva; so that it is perfectly secured and corked up, as it were, from all inclemencies. The cause why the slugs are able to endure the cold so much better than shell-snails is, that their bodies are covered with slime, as whales are with blubber.

Snails copulate about midsummer, and soon after deposit their eggs in the mould by running their heads and bodies under ground. Hence the way to be rid of them is to kill as many as possible before they begin to breed.

Large, grey, shell-less cellar-snails lay themselves up about the same time with those that live abroad; hence it

is plain that a defect of warmth is not the only cause that influences their retreat.—WHITE.

SNAKE'S SLOUGH.

-There the snake throws her enamell'd skin."

-SHAKESPEARE's Midsummer Night's Dream.

About the middle of this month (September) we found in a field near a hedge the slough of a large snake, which seemed to have been newly cast. From circumstances it appeared as if turned wrong side outward, and as drawn off backward, like a stocking or woman's glove. Not only the whole skin, but scales from the very eyes are peeled off, and appear in the head of the slough like a pair of spectacles. The reptile, at the time of changing his coat, had entangled himself intricately in the grass and weeds, so that the friction of the stalks and blades might promote this curious shifting of the exuviæ.

It would be a most entertaining sight could a person be an eye-witness to such a feat, and see the snake in the act of changing his garment. As the convexity of the scales of the eyes in the slough is now inward, that circumstance alone is a proof that the skin has been turned; not to mention that now the present inside is much darker than the outer. If you look through the scales of the snake's eyes from the concave side-viz., as the reptile used them, they lessen objects much. Thus it appears from what has been said, that snakes crawl out of the mouth of their own sloughs, and quit the tail part last, just as eels are skinned by a cook maid. Whilst the scales of the eyes are growing loose, and a new skin is forming, the creature in appearance

must be blind, and feel itself in an awkward, uneasy situation.-WHITE.

I have seen many sloughs or skins of snakes entire, after they have cast them off; and once in particular I remember to have found one of these sloughs so intricately interwoven amongst some brakes that it was with difficulty removed without being broken; this undoubtedly was done by the creature to assist in getting rid of its encumberance.

I have great reason to suppose that the eft or common lizard also casts its skin or slough, but not entire like the snake; for on the 30th March 1777 I saw one with something ragged hanging to it, which appeared to be part of its old skin. -MARKWICK.

OBSERVATIONS ON VEGETABLES.

TREES, ORDER OF LOSING THEIR LEAVES. ONE of the first trees that becomes naked is the walnut; the mulberry, the ash, especially if it bears many keys, and the horse-chestnut come next. All lopped trees, while their heads are young, carry their leaves a long while. Apple-trees and peaches remain green very late, often till the end of November: young beeches never cast their leaves till spring, till the new leaves sprout and push them off; in the autumn the beechen-leaves turn of a deep chestnut colour. Tall beeches cast their leaves about the end of October.

SIZE AND GROWTH.

Mr. Marsham of Stratton, near Norwich, informs me by letter thus "I became a planter early; so that an oak which I planted in 1720 is become now, at one foot from the earth, twelve feet six inches in circumference, and at fourteen feet (the half of the timber length) is eight feet two inches. So if the bark was to be measured as timber, the tree gives 116 feet, buyer's measure. Perhaps you never heard of a larger oak while the planter was living. I flatter myself that I increased the growth by washing the stem, and digging a circle as far as I supposed the roots to extend, and by spreading sawdust, etc., as related in the Phil. Trans. I wish I had begun with beeches (my favourite trees as well as yours); I might then have seen very large trees of my own raising. But I did not begin with beech till 1741, and then by seed; so that my largest is now at five feet from the ground, six feet three inches in girth, and with its head spreads a circle of twenty yards diameter. This tree was also dug round, washed, etc.STRATTON, 24th July, 1790."

The circumference of trees planted by myself at one foot from the ground (1790):—

The great oak in the Holt, which is deemed by Mr. Marsham to be the biggest in this island, at seven feet from the ground, measures in circumference thirty-four feet. It has in old times lost several of its boughs, and is tending to decay. Mr. Marsham computes that at fourteen feet length this oak contains 1000 feet of timber.

It has been the received opinion that trees grow in height only by their annual upper shoot. But my neighbour over the way, whose occupation confines him to one spot, assures me that trees are expanded and raised in the lower parts also. The reason that he gives is this: the point of one of my firs began for the first time to peep over an opposite roof at the beginning of summer; but before the growing season was over, the whole shoot of the year, and three or four joints of the body beside, became visible to him as he sits on his form in his shop. According to this supposition, a tree may advance in height considerably though the summer shoot should be destroyed every year.

FLOWING SAP.

If the bough of a vine is cut late in the spring, just before the shoots push out, it will bleed considerably; but after the leaf is cut, any part may be taken off without the least inconvenience. So oaks may be barked while the leaf is budding; but as soon as they are expanded, the bark will no longer part from the wood, because the sap that lubricates the bark and makes it part is evaporated off through the leaves.

RENOVATION OF LEAVES.

When oaks are quite stripped of their leaves by chaffers, they are clothed again soon after midsummer with a beautiful foliage; but beeches, horse-chestnuts, and maples, once defaced by those insects, never recover their beauty again for the whole season.-WHITE.

ASH TREES.

Many ash trees bear loads of keys every year, others never scem to bear any at all. The prolific ones are naked