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mach of horses, and sometimes, though less frequently, in the intestines. Here they hang in clusters of from half a dozen to more than a hundred, adhering to the inner membrane of the stomach, by means of two small hooks or tentacula at their heads, whose points turn outward.

When they are removed from the stomach, they will attach themselves to any loose membrane, even to the skin of the hand. To do this, they draw back their hooks, almost entirely within their skin, till the two points come close to each other; then, keeping them parallel, they pierce through the membrane, and immediately afterwards expand them in a lateral direction, and by these means become perfectly fixed.

Their food is probably the chyle, that white juice which is formed in the stomach by the digestion of the food, and which is afterwards converted into blood. This they suck in at a small longitudinal aperture, situated between the hooks.

From their slowness of growth, and the very small quantity of food they require, it has been found extremely difficult to destroy the larvæ of this fly by any medicine or poison, that could be thrown into the stomach. They are, however, not now considered so injurious to horses as they formerly were, and therefore the difficulty of their extirpation seems not a matter of so much consequence as people have imagined.

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The mode pursued by the parent-fly to obtain for its offspring a situation in the stomach of the horse, is singular the female, when the time for laying her eggs is at hand, approaches on wing that part of the horse, where she intends to deposit the egg; this she does with her body nearly upright, and her tail, which is lengthened out for the purpose, bent inwards: she scarcely appears to settle, but merely touches the hair, with the egg held out on the projected point of the abdomen. The egg adheres by means of a glutinous liquor secreted with it. She then leaves the horse, goes to a little distance, and prepares a second egg; then, poising

herself near the part, deposits this in the same way. The liquor dries, and the egg becomes firmly glued to the hair: this is repeated by various flies, till 400 or 500 eggs are sometimes laid on one horse.

The inside of the knee is the part on which these flies principally deposit their eggs; and next to this they fix them on the sides, and the back part of the shoulder : but almost always in places that are liable to be licked by the tongue. When these eggs have remained on the hairs four or five days, they become ripe, after which the slightest application of warmth and moisture is sufficient to bring them into life. If at this time the tongue of the horse touch the egg, its lid is thrown open, and a small, active worm is produced, which readily adheres to the surface of the tongue, and is thence conveyed with the food to the stomach.

It is, however, fortunate for the horses, that this insect is exposed to so many hazards, that scarcely one in a hundred arrives at the perfect state of a fly. The eggs, when ripe, often hatch of themselves, and the larvæ crawl about till they die; others are washed off by the water. When in the mouth of the animal, they have to undergo the ordeal of the teeth and mastication; and many pass entirely through the intestines with the food. When the larvæ arrive at full growth, and are voided along with the dung, many are either dropped into mud or water, others are crushed to death by being trod upon, and others are picked up and devoured by birds. The perfect fly is very tender, and but ill sustains the changes of weather; and cold and moisture, in any considerable degree, are probably often fatal to it.

THE SHEEP GAD-FLY*.

The manner in which the Gad-fly of the sheep deposits its egg, has seldom been noticed; nor is it easy,

DESCRIPTION. The abdomen is spotted with black and white; and the head is white and punctured. The eyes are

from the obscure and rapid motion of this insect, to discern the exact manner in which this is accomplished. The moment the flies touch the noses of the sheep, the animals shake their heads, and strike the ground violently with their fore-feet: at the same time holding their noses to the earth, they run away, looking about them on every side, to see if the flies pursue. They also appear to smell the grass as they go, lest the insects should be lying in wait for them. If they observe one, they gallop back, or take some other direction. As they cannot, like cattle, take refuge in the water, they have recourse to a rut, or a dry dusty road, where they crowd together during the heat of the day, with their noses held close to the ground. This renders it difficult for the fly conveniently to get at the nostril. It is probably from repeated attacks of the gad-fly, and the consequent rubbing against the ground, that the nostril often becomes inflamed and sore.

OF THE TIPULÆ, OR CRANE-FLIES*.

In their general form, the Tipulæ have a general resemblance to the gnats, but they are easily distinguished from those insects, by having expanded wings, and being destitute of the long proboscis which is so conspicuous in the gnats. From the commencement of spring until the beginning of autumn, the larger kinds of Tipulæ are to be seen in great numbers in pastures and meadows. Some of the species lay their eggs upon the ground amongst the grass, and others in the hollows

marbled; and the wings are pellucid, and punctured at the base.

SYNONYMS. Oestrus ovis. Linnæus.-L'Oestre des Moutons. Latreillle.

* The Tipulæ have a very short membranaceous proboscis, the back of which is grooved, and receives a bristle. The feelers are two, incurved, thread-shaped, and longer than the head; and the antennæ are, for the most part, filiform.

of decayed trees. The larva are without feet, soft, and cylindrical.

Both the larva and chrysalids of the smaller Tipulæ are found in water, and are very various, both in size and colour. Some are furnished with a pair of arms; and others are enclosed in cylindrical tubes, open at the ends. The latter swim nimbly, but the former always remain in holes which they have formed in the banks of rivulets. Some of the species spin a silken case round part of their body. Their whole frame is, in general, so very tender, that, in some of the species, a touch only is sufficient to crush them.

THE MEADOW CRANE-FLY, OR LONG-LEGS

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In grass lands and clover stubbles, the grubs or larvæ of these flies are often extremely injurious; and even crops of grain, in the vicinity of meadows, are occasionally much damaged by them. They feed on the roots of plants, and destroy the tender shoots, at the time that they are beginning to make their appearance above the surface of the ground.

About the middle of August the females usually commence the operation of depositing their eggs. In this act they bend their tails to the roots of the grass, and move about from place to place, leaving a few eggs in each spot where they alight. The body of each female contains several hundred eggs; and, upon being squeezed, these will quit the tail one by one, with a sudden spring. If the weather be fine, nearly the whole of the eggs are deposited by the end of the first week in September. The larva or grubs usually begin to quit the

DESCRIPTION. This insect is eight or nine lines in length. Its body is of a cinereous brown colour. The antennæ in both sexes are filiform. The wings are transparent, and brown on their exterior margin.

SYNONYMS. Tipula oleracea. Linn.-La Tipule des Près. Tigny. The larvæ has, among farmers, the general name of "the grub."

eggs some time in the month of February, and they continue in this state during the whole of the summer.

In the day-time the larvæ are generally to be found at the depth of from half an inch, to an inch and a half, below the surface of the ground. It is supposed that they do not come much above-ground, even in the night, but that they feed chiefly below the surface.

These insects are destroyed in great numbers by rooks, jackdaws, starlings, lapwings, and other birds. About the beginning of August they assume their pupa state, and before the end of that month become winged insects.

In an excellent paper communicated to the Holderness Agricultural Society, by Mr. Stickney, of Ridgemont, it is stated that, in the destruction of these insects, lime, as had generally been supposed, has not any material effect. Nor does this gentleman imagine, that any other substance can, on an extensive scale, be successfully applied to the soil to destroy them.

THE WHEAT-FLY*.

In July, 1795, Mr. Marsham had been informed, that an insect, which threatened much mischief, had made its appearance among the wheat of a gentleman, a friend of his, in Hertfordshire. Some of the ears were brought to him for examination; and, on opening those that seemed diseased, he found in many an orange-coloured powder, and in several, one or two very minute larvæ of a yellow colour. On applying a magnifier, for they were too minute for examination with the naked eye, he supposed them to be the larvæ of a small species of Musca; but they have since been discovered to be a species of Crane-flies. They were thicker at one end

DESCRIPTION. The Wheat-fly is about the twelfth of an inch in length. Its body and legs are of a dull yellow colour; and the wings are whitish, with a fringed margin.

SYNONYM. Tipula Tritici. Linn. Tran.

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