grown strong in you for my favourite pursuit; and you now anticipate with a laudable eagerness, the discoveries that you may make respecting the history and economy of this most interesting department of the works of our Creator. I hail with joy this intention to emulate the bright example, and to tread in the hallowed steps of Swammerdam, Leeuwenhoek, Redi, Malpighi, Vallisnieri, Ray, Lister, Reaumur, De Geer, Lyonnet, Bonnet, the Hubers, &c.; and I am confident that a man of your abilities, discernment, and observation will contribute, in no small degree, to the treasures already poured into the general fund by these your illustrious predecessors.

I feel not a little flattered when you inform me that the details contained in my late letters relative to this subject, have stimulated you to this noble resolution.—Assure yourself, I shall think no labour lost, that has been the means of winning over to the science I love, the exertions of a mind like yours.

But if the facts already related, however extraordinary, have had power to produce such an effect upon you, what will be the momentum, when I lay before you more at large, as I next purpose, the most striking particulars of the proceedings of insects in society, and show the almost incredibly wonderful results of the combined instincts and labours of these minute beings? In comparison with these, all that is the fruit of solitary efforts, though some of them sufficiently marvellous, appear trifling and insignificant: as the works of man himself, when they are the produce of the industry and genius of only one, or a few individuals, though they might be regarded with admiration by a being who had seen nothing similar before, yet when contrasted with those to which the union of these qualities in large bodies has given birth, sink into nothing, and seem unworthy of attention. Who would think a hut extraordinary by the side of a stately palace, or a small village when in the vicinity of a populous and magnificent city?

Insects in society may be viewed under several lights, and their associations are for various purposes and of different durations.

There are societies the object of which is mutual defence; while that of others is the propagation of the species. Some form marauding parties, and associate for prey and plunder;—others meet, as it should seem, under certain circumstances, merely for the sake of company;—again, others are brought together by accidental causes, and disperse when these cease to operate;—and finally, others, which may be said to form proper societies, are associated for the nurture of their young, and, by the union of their labours and instincts, for mutual society, help, and comfort, in erecting or repairing their common habitation, in collecting provisions, and in defending their fortress when attacked.

With respect to the duration of the societies of insects, some last only during their first or larva state; and are occasionally even restricted to its earliest period;—some again only associate in their perfect or imago state; while with others, the proper societies for instance, the association is for life. But if I divide societies of insects into perfect and imperfect, it will, I think, enable me to give you a clearer and better view of the subject. By perfect societies I mean those that are associated in all their states, live in a common habitation, and unite their labours to promote a common object;—and by imperfect societies, those that are either associated during part of their existence only, or else do not dwell in a common habitation, nor unite their labours to promote a common object. In the present letter I shall confine myself to giving you some account of imperfect societies.

Imperfect societies may be considered as of five descriptions:—associations for the sake of company only—associations of males during the season for pairing—associations formed for the purpose of travelling or emigrating together—associations for feeding together—and associations that undertake some common work.

The first of these associations consists chiefly of insects in their perfect state. The little beetles called whirlwigs (Gyrinus),—which may be seen clustering in groups under warm banks in every river and every pool, and wheeling round and round with great velocity; at your approach dispersing and diving under water, but as soon as you retire resuming their accustomed movements,—seem to be under the influence of the social principle, and to form their assemblies for no other purpose than to enjoy together, in the sunbeam, the mazy dance. Impelled by the same feeling, in the very depth of winter, even when the earth is covered with snow, the tribes of Tipulariæ (usually, but improperly, called gnats) assemble in sheltered situations at midday, when the sun shines, and form themselves into choirs, that alternately rise and fall with rapid evolutions[1]. To see these little aëry beings apparently so full of joy and life, and feeling the entire force of the social principle in that dreary season, when the whole animal creation appears to suffer, and the rest of the insect tribes are torpid, always conveys to my mind the most agreeable sensations. These little creatures may always be seen at all seasons amusing themselves with these choral dances; which Mr. Wordsworth, in one of his poems[2], has alluded to in the following beautiful lines:

Another association is that of males during the season of pairing. Of this nature seems to be that of the cockchafer and fernchafer (Melolontha vulgaris and Amphimalla solstitialis), which, at certain periods of the year and hours of the day, hover over the summits of the trees and hedges like swarms of bees, affording, when they alight on the ground, a grateful food to cats, pigs, and poultry. The males of another root-devouring beetle (Hoplia argentea) assemble by myriads before noon in the meadows, when in these infinite hosts you will not find even one female[3]. After noon the congregation is dissolved, and not a single individual is to be seen in the air[4]: while those of M. vulgaris and A. solstitialis are on the wing only in the evening.

At the same time of the day some of the short-lived Ephemeræ assemble in numerous troops, and keep