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water, and, sinking to the bottom, they are soon hatched. Although the life of the insect, in its perfect state, is so very short, such is by no means the case in the larval stage of its existence. In some species two or three years elapse between the hatching of the egg and the appearance of the insect in the winged state. That time is passed at the bottom, where the insect undergoes various transmutations, each gradually fitting it for its brief existence in another element. Unlike the phryganidae, these larvae do not construct cases in which to take up their residence, but they hide themselves under stones and among the roots of plants — sometimes collecting together in great numbers. Some excavate holes in the mud at the bottom and along the banks below the surface of the water. These retreats consist of two tunnels, each having an external opening, and connected inside at the extremity. The object of this contrivance is to allow free ingress and egress to the inmate. Were there but one straight perforation the insect would be obliged to turn itself quite round to effect its object, which would be attended with great inconvenience, from the diameter of the tunnel being little larger than that of its own body. The burrowing kinds seldom quit their retreats, but the others range about very actively, feeding upon vegetable matter. It is stated by some writers that the former feed upon the clay, in which their holes are made. Swammerdam, the celebrated Dutch naturalist, found that substance in their stomach and intestines. “It is therefore most probable,” says Mr. Westwood, “ that when the larva has assimilated the decaying vegetable matter contained in the mud, the earthy particles are discharged. The larva is provided with six legs, and what are regarded by some writers as a row of fins on each side of the body. These fin-like appendages, however, are, with greater probability, considered by other writers to be the organs of breathing—answering to the lungs of land animals, and to the gills of fishes. They are constantly in motion, and are pervaded by little tubes, very curiously arranged, through which the air is supposed to pass. The general form of the larvae resembles that of the perfect insect, with the exception, of course, of wings, and the likeness becomes more and more apparent after each moulting. Its last change, in the water, is into the pupa state, and when this has taken place and the atmosphere is of the proper temperature, the insect rises to the surface, and, emerging from its confinement in the pupa skin,
appears in the form of a delicate fly. But its transmutations are not yet complete, for the newly produced insect makes early use of its wings to remove to the nearest bank or tree, where it undergoes its final metamorphosis—shedding the whole of the delicate skin with which not only its body, but its wings, legs, and whisks were govered. The cast off skin remains behind, retaining for a short time the exact form of the insect.” After this final change the fly is brighter in colour, its wings are more shining and transparent, and its whisks are considerably longer. The insect is at last, after so much labour and danger, in its perfect or imigo state, and being now furnished with organs to continue its species it loses no time in fulfilling the Divine command. Indeed, it has no time to lose. The new life, or rather state of existence, into which it is launched is but a very brief one — its very moments are numbered. The parental duties are hastily commenced, and the life of both the male and female insect ceases with their accomplishment. The duns and other smaller species lay their eggs while sitting on the water, but the May-fly, and some others, do so while springing up and down in the air, from the surface. The whole number deposited by a single May-fly has been calculated at eight hundred, which, perhaps, is considerably more than that deposited by the smaller species. Very little time is occupied in depositing them, as they are arranged in two packets, the contents of each being cemented together with a substance soluble in water. These packets are deposited at the same moment, and the grains of which they are composed separate, and become dispersed in the water, to be hatched as before described. To counterbalance its immense prolificacy, the enemies of the little insect are numerous and voracious. The swallow which skims the pool, and the trout which breaks its surface, immolate thousands when in the very act of propagating their kind—and the latter, too, are not indifferent to their future winged prey when in the state of crawling grubs at the bottom of the water. The blue dun appears upon the water towards the end of February, or earlier in mild weather, and continues in a succession of species and varieties throughout the season. After the blue dun has changed its first-winged coating, in the manner just described, it assumes a different colour and is called the red spinner—in which state it lays its eggs. Its imitation in the dun state, however, is most used by anglers — particularly in the early part of the season. “The term dun,” observes Mr. Ronalds, “seems to have been applied in a general sense to the different species of ephemeridae in the first winged state (except those of the largest size) another name being added to designate each species—as the blue dun, yellow dun, &c. In like manner the term spinner seems to have been applied as a general name for the final or perfect state of the same insect — another name, also, being added to distinguish each species, as the red spinner, the great red spinner,” &c. The latter is the meta
* This wonderful operation may be witnessed by any one who will take the trouble to catch a blue dun, or any other ephemeral fly, and place it under a wine glass. Or even that trouble may be saved by watching, for a few minutes, the same kind of flies alighted on the sleeve of his coat during his summer-evening's ramble by the river side. These insects will have availed themselves of his presence for the express purpose of undergoing the operation, and if he be a lover of nature, the contemplation of such a sight will prove an ample return for the convenience afforded by the said sleeve, and for the slight interruption to his fishing or his walk which that contemplation may have occasioned. To the dwellers by the Axe we need not mention Cloakham bridge as a favourite resort of ephemeral flies for the purpose mentioned, nor as an excellent place for studying the economy of many other aquatic insects’; to say nothing about its claims to their attention for affording a pleasant prospect of varied scenery, and for the study of other portions of animate and inanimate nature — from the beaux and belles of Axminster, and the groves and lawn of Cloakham, downwards.