Bartram, in the Philosophical Transactions, "I observed many deformed water-insects, called Hexapodes, creep out of the water and fix on shrubs and rushes. In this situation they continued but a few hours before their backs split open, and from the deformed creatures sprung out beautiful flies with bright shining wings, all of which, in less than an hour afterwards, attained their complete dimensions." At the first exclusion of the insect, the wings are weak and tender, and folded into a very narrow compass. During their unfolding, and till they become perfectly dry, it continues almost motionless; but they are no sooner completed, than the little animal commences an inhabitant of the air, and would now be as effectually destroyed by continual submersion under water, as the larva would before have been by exposure to the air.

In their complete state, the Dragon-flies, as I have already remarked, feed on the smaller insects; and they are also remarkable for the vigour and celerity of their flight. The Rev. Revett Sheppard informs me, that, in the summer of 1801, he sat for some time by the side of a pond, to observe a large Dragon-fly as it was hawking backward and forward in search of prey, when suddenly, a white butterfly, Papilio Brassica, flew past. The Dragon-fly instantly attacked and caught it in the air, then settled on a twig, close at hand, to eat it at leisure. It bit off the wings, and then, in less than a minute, devoured the body.

These insects, which are very common in England, delight in sunshine, and are seldom to be seen abroad in cloudy weather, hiding themselves, during the absence of the sun, under the leaves and branches of trees.

OF THE EPHEMERE, OR DAY-FLIES*. The Ephemeræ differ in many respects from all

The mouth of the Ephemera has no jaws, but is furnished with four very short thread-shaped feelers. The antennæ are

other insects. Their larvæ live in water for three years, the time they consume in preparing for their change, which is performed in a few moments. The larva, when ready to quit that state, rises to the surface of the water, and, instantaneously freeing itself from its skin, becomes a chrysalis. This chrysalis is furnished with wings it flies to the nearest tree or wall, and, there settling, it at the same moment quits a second skin, and becomes a perfect Ephemera. In this state all the species live but a very short time, some of them scarcely half an hour; having no other business to perform than that of continuing the race. They are called the insects of a day; but few of them ever see the light of the sun; being produced after sunset, during the short nights of summer, and dying long before the dawn. All their enjoyments, therefore, seem confined entirely to their larva state.

The Ephemera are very frequent near waters, and in some places they multiply enormously. About Laz, in Carniola, a province in Germany, we are informed by Scopoli, that they are so numerous in the month of June, that they are used as manure; and if each farmer cannot obtain more than twenty cart-loads, the harvest is considered a bad one.

The larvæ scoop out dwellings in the banks of rivers. These consist of small tubes, made like syphons, with two holes, the one serving for an entrance, and the other as an outlet; and these are so numerous, that the banks of some rivers are observed to be full of them. When the waters decrease, they dig fresh holes lower down. The flies are produced nearly all at the same instant, and in such numbers, as even to darken the air.

The females, aided by the threads of their tails, and the flapping of their wings, support themselves on the sur

short and thread-shaped; and above the eyes there are two or three large stemmata. The wings are erect, (the lower ones much the shortest,) and the tail is terminated by long hairs or bristles.

A

face of the water, and, in an almost upright position, drop their eggs in little clusters into the water. single insect will sometimes lay seven or eight hundred eggs.

THE COMMON EPHEMERA, OR DAY-FLY*.

M. de Reaumur has described very accurately the metamorphosis of a kind of Ephemera, which, except in the time of the year when it is produced, and the duration of its fly-state, seems much to resemble the present species, and is, probably, only a variety of it.

On the nineteenth of August, 1738, he waited for some time after sunset on the bank of the Seine, to see, as he had been informed he might, millions of Ephemeræ issue from the water, and rise into the air; and he was returning disappointed along with his servants, who were carrying a tub containing several lumps of earth full of holes and nymphæ, when scarcely had it been set on one of the steps of the stairs, than those who had the charge of it exclaimed, " What a multitude of Ephemeræ are here!" M. de Reaumur seized one of the lights, and ran to the tub. Every part of the earth that was above the water, was covered with Ephemeræ, some of which had just begun to put off their coverings, others had almost effected it, and others had entirely completed it, and were about to take wing. A storm of lightning and rain, which had been some time coming on, now drove him into the house; but, to prevent the Ephemeræ from flying entirely away in his absence, he had the precaution to cover the tub with a cloth. The violence of the rain continued for about half an hour, and on its ceasing he returned to the garden. On taking off the covering, he found the number of Ephemeræ

* DESCRIPTION. The tail has three filaments. The wings are brown and white.

SYNONYMS. Ephemera vulgata. Linnæus.-L'Ephémère commune, in France.

considerably augmented, and they continued to multiply for some time, as he stood watching them. The number already transformed, from the earth that the men had conveyed from the river, would have been sufficient to have filled the tub; but this number was prodigiously augmented by the accession of strangers, which were attracted by the light from all quarters. He again spread the cloth over the tub, and the light was held above it immediately the cloth was almost concealed by the vast multitudes which alighted upon it. But what he had seen about the tub, was nothing to what he saw, when he went again to the side of the river. "The numbers of Ephemeræ," says he, "which filled the air, can neither be expressed nor conceived. When snow falls thickest, and in the largest flakes, the air is never so completely filled with these, as that which surrounded us, was with Ephemeræ. Scarcely had I remained a few minutes in one place, when the step on which I stood, was covered in every part with their bodies, to the depth of two or three, and in some places even of more than four inches. The whole surface of the water, for at least six feet from the bank, was entirely covered with a coat of Ephemeræ; those which the current carried off, were more than replaced by those which fell continually in that place. I was several times compelled to abandon my station, by retreating to the top of the stair, not being able to sustain the shower of Ephemera, which, not falling so perpendicularly as an ordinary shower, or with an obliquity equally constant, struck me uninterruptedly, and, in a very troublesome manner, on all parts of the face: my eyes, nose, and mouth, were filled with them. It was an unpleasant post to hold the candle on this occasion; the man who held it, had his whole body covered with these flies in an instant; they rushed to him from all parts in such quantities, as to oppress him. The light of the candle occasioned a spectacle altogether different from any thing that can be observed in any kind of meteorological shower: it was indeed enchanting. The most un

observing of my domestics could scarcely ever have been tired of admiring it. No astronomic sphere was ever formed so complicated as this, nor was furnished with so many circular zones in every possible direction, having the flame of the candle for their common centre. Their number appeared to be infinite, having all possible degrees of obliquity with respect to each other. Each zone was formed by an uninterrupted string of Ephemeræ, which, as if tied together, followed each other close in the same line: they seemed to form a circular ribbon of silver, deeply indented on its edges; a ribbon formed of equal triangles put end to end, so that the angles of those that followed, were supported by the base of that which preceded, the whole moving round with great quickness. Ephemera, whose wings only were then distinguishable, and which circulated around the light, formed this appearance. Each of these flies, after having described one or two orbits, fell to the earth, or into the water, but without having been burned by the candle." At the end of about half an hour from its commencement, the great shower began to abate, and in little more than an hour, scarcely any Ephemeræ could be seen above the river, and no more came near the candle. This phenomenon, M. de Reaumur found, upon examination, took place every evening, during most of the summer months; and usually commenced about the same hour.

In this short period of existence, the female appears to have no other business than to lay her eggs. These are contained in two large packets, each enclosing from 300 to 400. They are both extruded from the body at the same time, through two openings formed for the purpose, and they fall together in one accumulated mass, upon the water. To enable the creature to extrude these, and at the same time to fill up the great vacuum in the abdomen, that must instantaneously take place, the fly is provided with a couple of small bladders, which it has the power of filling with air.

The singular quickness and ease, with which these