either four or five joints. The second is the Erachocera, or Short-horned Diptera, in which the antennae have not more than three distinct joints, and the palpi not more than two joints, and often only one.

The first Division embraces those insects which are popularly known as Grnats and Daddy-long-legs, and scientifically as Culicidae and Tipulidae. We will begin with the former, and take as an example the Common Gtnat {Gulex ^i'piens^, the male of which is represented on Woodcut LXIX. Fig. 3.

In this family, the parts of the mouth are developed into a long beak, rather thickened at the end, and being generally about half as long as the head and body of its owner. The beak is better studied from a female than a male specimen, as only in the former is the complicated structure fully developed. The beak consists altogether of seven pieces, some being used as lancets, which the insect can drive into the substances on which it feeds, and the others act as sheaths or strengthening' pieces. Owing to the very small size of the Gnat the dissection of the beak is a very difficult process. Mr. Westwood, however, has succeeded in accomplishing it, and his account is briefly as follows. ‘ All the parts of the mouth of a mandibirlated insect are here observable. There is a broad and hollow lancet-like piece, representing the upper lip (which is the most robust part of the mouth, except the labium) ; a pair of slender, needle-like pieces, as the mandibles, which are serrated on the outside at the tip ; a second pair of similar, but much more slender organs, dilated at the base, representinothe maxillce, to the bases of which the palpi are attached ; a very slender, needle-like instrument, representing the tongue, and the outer tubular canal, in which the others lodge when at rest representing the loiver lip.’

I have slrghtly abridged the above description, and inserted the italics, in order to point out more strongly the analysis of the parts, so that the reader may see that the beak of the Gnat, with its apparatus of lancets and sirction-tube, is formed of exactly the same elements as the mouth of the Stag-Beetle which is represented on j)age 9.

I strongly recommend any reader who has access to a micro scope to examine carefully the head and thorax of the Gnat oth male and female. The Gnat is a singularly unpleasant

insect in a room, but it is marvellously beautiful under the microscope, and should be examined both with direct and transmitted light, and with a succession of powers, beginning at the lowest and ending at the highest, so as to gain its beauties of detail by degrees. The antenna of the male, for example, which is represented on Woodcut LXIX. Fig. h, is a wonderfully beautiful object. There are fourteen joints, and each joint is furnished with a whorl of long hair, disposed as seen in the illustration. The same portion of the female has the whorl of hair so short as to be invisible without the aid of a lens. Then again, the beak, the wings, the limbs, and the body generally are studded with beautiful scales, resembling in form those of the Lepidoptera, but more deeply grooved, and having the ridges prolonged beyond the end, so as to form a row of little spikes. These scales are so plentiful, so easily detached from the insect, and so readily recognised, that if a Grnat should have heen kept in a box in which various other insects have been placed, the microscope will detect upon all the later comers some of the scales of their predecessor.

These scales give to the insect a splendour of colom-ing which cannot be appreciated until the microscope is brought to bear on it, and which entirely baffles any power of description. So I recommend my readers to look for themselves, and to place the first Grnat that they catch under a microscope, taking care to concentrate upon it as brilliant a light as they can obtain. When they have done this, they will begin to realise some of the wonders of Fairyland, and to see actually before their eyes splendours which the most daring fairy tale has but faintly pictured. Dull and colourless as the Grnat may appear to the unaided eye, it has only to be placed under the revealing glass of the microscope to blaze out in a magnificence which would pale all the fabled glories of Aladdin’s fairy palace. I have no doubt that all this splendour is perfectly visible to the eyes of the insects themselves, and that the beauties which are hidden from us until we have recourse to artificial vision, are seen and appreciated by the insects whose bodies they adorn.

To descend to more prosaic details — though after all, tlie history of every insect is really a poem — we must bear in mind that, though both sexes partake of tins splendid apparel, the male does not possess the skin-piercing lancets with which the

mouth of the female is armed. The male Grnat, in fact, is

perfectly harmless, and it is to the female alone that we owe the annoyances which have rendered the sight of the delicate little insect hateful to our eyes, and the really musical hum of its wings a terror to our ears.

In this favoured country, we know little of the powers of the Gnat. We often suffer very considerable inconvenience and annoyance from them, as I can testify, having twice in the summer of 1870 lost the use of my right hand for a week together in consequence of a single gnat-bite. In both cases the bite took place just at the junction of the thumb and the wrist, and in both cases the effect was the same. The hand swelled until it looked like a boxing-glove, was purple in colour where it was not crimson, the fingers could neither be closed nor opened, and the only mode of subduing the fierce heat of the hand was by carrying it in a sling, and having a piece of ice fastened on it over the spot where the Gnat had inserted her beautiful but objectionable beak. I did not fully recover the use of the hand for full three weeks after the bite had been inflicted.

Such being the effect of a single gnat-bite in England, we may form some idea of the terrors of this little insect in the countries where it is known as the Mosquito, where the venom of its bite is increased tenfold, and its numbers are multijffied by millions. Life is absolutely rendered a burden by these tiny insects, whicth assume to themselves the mastery of the country in which they live. There are some parts of the world where the Gnat has absolutely driven the human inhabitants from the land into the water. For some reason, not at present ascertained, the Gnat never lives at any distance from land. It may travel inland for miles from the spot where it was hatched, but it will not willingly travel to any distance over the water. Knowing this peculiarity of constitution, the inhabitants of such spots have taken advantage of it, and made their homes on the bosoms of lakes, supporting them on piles driven into the ground.

Here we really have no idea of the vast Gnat armies that besiege other lands. Even in parts of Russia, as we are told by Hr. Clarke from his own experience, no amount of gloves, handkerchiefs, and thick clothing could defend man or woman

from the Grnats. On one occasion, on a close sultry night, t when not the slightest breeze was stirring, and in consequence every breath of air was priceless, he was driven to take refuge in his carriage, and to shut all the windows. Now closed windows, although they may exclude those Gnats which are outside the carriage, cannot eject those that are already in it, and they were so numerous that Dr. Clarke was forced to tie several handkerchiefs over his head, in spite of the sultry • weather. Setting these handkerchiefs at defiance the Gnats got into his mouth, crawled up his nostrils, and forced themselves into his ears. In despair, he tried to light a lamp and succeeded, but the flame was instantly extinguished by the ill Gnats, who flew to the light, and poured in such numbers down the glass chimney that a large conical heap of their bodies lay over the burner. ||.

As for remedies, it is no easy matter to recommend them. I have an idea that the remedy must suit the idiosyncrasy of the sufferer, and that a prescription which suits one person admirably will have little or no effect upon another. For my own part, ; I have found that arnica serves to keep down the swelling and irritation better than anything else. This year, 1871, 1 have been bitten several times, but have applied arnica, and found that it saved a vast amount of torture. There was some swelling and considerable irritation, lasting for several days, but the aggravated symptoms of the preceding year did not show themselves.

The life history of the Gnat is very interesting. When the female is about to deposit her eggs, she proceeds to the nearest water, and there sets about the last task of her life. Placing her front legs on a piece of floating stick, straw, or anything that will support her tiny weight, she allows the middle pair of legs to rest on the surface of the water, and crosses the hind pair so as to look like the capital letter X. She then deposits a rather long and spindle-shaped egg, and places it upright with the base downwards in the angle of the X. Another egg is quickly placed by the side of the first, and followed by | others, all of which are glued together by a cement which is ^ not affected by water. Guided by the crossed legs, the eggs are formed into a boat-like shape, and are then left to float on the surface of the water.

These little egg-boats are quite plentiful in the summer-

time, and any number can be taken for the purpose of experimenting. Their shape very much resembles that of the lifeboat now in use, and, like the life-boat, the egg -boat cannot be sunk, and if capsized rights itself again immediately. Even if some of these boats be placed in a vessel of water, and the contents of the vessel be poru’ed from a height into the pond, the little boats float at once to the surface like so many corks, and each, as it rises, assumes its proper position.

In due course of time the larva is hatched, pushes off the lower end of the egg, which opens like a little circular trapdoor, and allows itself to float off into the water. The larva is a quaint-looking little being, with a long body terminated at one end with a large round head, and at the other with a forked tail. When examined through the microscope the larva is a most cmious creature, the semi-transparency of the body rendering the internal organs almost as plainly visible as if there were no skin at all. The young and small larvae, which have just shed one of their successive skins, are better for microscopical examination than those of a larger size, because their integuments become more opaque with age. Through the centre of the body the digestive organs are marked by their darker hue, and just above them pulsates the ‘ dorsal vessel ’ which stands insects in the stead of a heart.

On either side of the body runs a rather dark tube, and the two, joining each other at the angle of the fork of the tail, turn off to one of the points of the fork, and run side by side along it. These tubes are the two principal canals of the respiratory apparatus, as is easily seen by putting a high power to the microscope — say, an object-glass magnifying some two hundred diameters. When this is done, the spiral thread which is coiled round the breathing tube of insects becomes plainly visible, and at once declares the character of these dark vessels. At regular intervals smaller vessels branch off to the other parts of the body, and the tubes are Anally lost in the comparatively opaque head.

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