because the aperture is so small that they could not possibly pass through it when their wings were thoroughly expanded and dried. Of what form and colour these wings might be, was for a long time a mystery. Mr. Westwood, who first opened a nest, carefully dissected some of the pupæ, and by cautiously softening the withered membranes in warm water, succeeded in spreading out the wings sufficiently to learn the general form of the nervures and the shape of the "cells," as the spaces between the nervures are named.

Specimens of the perfect insect have now been obtained, and are seen to be butterflies closely resembling in shape the lovely heliconidae, which are so plentiful in Southern America, but of very simple colours, the general hue being blackish brown, diversified by a broad, but indistinctly marked white band across the wings. Examples of the nest have lately been sent to Vienna, but any one who wishes to see the specimen from which the above sketch and description were taken, may do so by visiting the museum at Oxford, where the perfect butterflies may also be seen. The scientific name of the butterfly is Eucheira socialis.

ON the upper part of the same illustration may be seen a curious object, that looks something like a flattened pincushion fastened to the branches. This is the nest of a social insect, and is, I believe, an unique specimen. It was brought from Tropical Africa by Vernon Wollaston, Esq. and is so remarkable as to deserve a detailed description.

In length it measures eight inches, and in width five and a half inches, its depth being about three inches. The aspect of the exterior gives but little promise of the exceeding strength of the structure, which is as hard and elastic as the side of a silk hat, rebounding when pressed in precisely the same manner. When cut, this covering is seen to be double, the outer case being very thin, and formed of orange-brown silken threads, and the inner being made of many successive layers of dark brown silk, so that it looks very like undressed leather.

The most extraordinary part of the nest, however, is the provision which is made for the exit of the inmates. Set upon different parts of the nest are thirteen or fourteen little conical protuberances, which do not project very far from the general

surface, and are quite inconspicuous. On examination, these prominences are seen to be composed of stiff silken threads, which converge to a point, precisely like those which guard the entrance of the emperor moth's cocoon, so that any inhabitant can crawl out, but no enemy can crawl in.

This nest, like the preceding, may be seen in the museum at Oxford.

THERE is a very pretty, very interesting, and very destructive insect, called by entomologists the SMALL ERMINE MOTH (Yponomeuta padella), which is very plentiful in this country, and by gardeners is thought to be much too plentiful. It can easily be recognised by its long narrow wings, the upper pair of which are soft silvery, or satiny white, spotted with black, and the lower pair dark brown. The expanse of the spread wings is about three quarters of an inch.

In its winged and pupal states the insect is perfectly harmless, but in its larval condition it becomes a terrible pest. Most caterpillars wage war singly on the foliage, and though they do much damage, their ravages are conducted in a desultory manner. The Small Ermines, however, band themselves together in hosts,

and march like disciplined armies to the attack, invading a district and completely devastating it before they proceed to another.

They live in large tents, placed among the branches of some tree, and composed of silken threads, which are loosely crossed and recrossed in various directions. From this centre the caterpillars issue in vast numbers, each individual spinning a strong silken thread as it proceeds, which acts as a guide to the nest, just as the fabled clue led through the intricacies of Rosamond's bower. When once these caterpillars have taken possession of a tree, they are sure to strip it of its leaves as completely as if the foliage had been plucked by hand. It is a very curious. sight to watch the systematic manner in which these troublesome insects set about their work, how they send out pioneers which lead the way to new branches, either by crawling up to them or by lowering themselves to them by means of their silken lifelines, and how soon they are followed by their ever hungry companions.

Perhaps the reader may wonder why the little birds do not eat these caterpillars. When they have nearly stripped the branch, they are very conspicuous, especially as they make their way from bough to bough along their silken bridges. Indeed, a proprietor of a garden that was much damaged by this moth did. once mention the immunity of the caterpillars as a proof that any tenderness to small birds was misplaced, saying that if the sparrows were half as insectivorous as I mentioned, they would long ago have eaten all the caterpillars.

Now, at the first glance, there seemed to be some reason in this remark; but a short look at one of the damaged trees explained the reason why the sparrows did not eat the caterpillars. The birds literally dared not approach the insects; for the silken threads which traversed the branches in all directions were an effectual barrier, striking against the wings and terrifying the poor birds. We all know that a few threads of fine cotton passed from bough to bough of a gooseberry-bush will deter any little bird from settling on it; and, in the same manner, the silken threads of the caterpillars deter the birds from settling on the branches. These threads are very elastic, and of marvellous strength, considering their tenacity, producing most uncomfortable sensations when they come across the face,

and being nearly as strong as the fibres spun by the common silkworm.

The caterpillar which works all this damage is rather slender, and is covered with black dots along the back.

ANOTHER well-known British insect which constructs social habitations is the GOLD-TAILED MOTH (Porthesia chrysorrhea), a familiar and beautiful insect, with wings of soft downy plumage, and snowy-white in colour, and a tuft of yellow hair at the end of the tail. The perfect insect may often be seen sticking on the trunks of trees in gardens, waiting until the evening, when it will fly off to its labours.

When the moth has laid its eggs, it plucks off the beautiful yellow tuft at the end of the tail, and with it forms a roof over the pile of eggs, laying the hairs so artificially as to make a perfect thatch. When the larvae are hatched, they retain their sociability, and spin for themselves a common domicile. This house is very remarkable. Viewed on the exterior, it is seen to be a bag-like structure of whitish silk, rather strong and tough, but very yielding.

One of these nests, which I found in Wiltshire, is now before me. It was found in a hedge, about two feet from the ground, and is rather a complicated structure. The scaffolding, so to speak, of the nest is formed by a horizontal spray of three small twigs, and it is strengthened by the long hedge-grass which crossed the spray. Seeds of different kinds are woven into the walls, so that a comparatively small portion of the silk is exposed to view.

When cut open, it shows a singularly beautiful structure within. There are several sheets of silken tissue, each becoming more delicate, and the innermost being white, shining like satin; whereas the outer covering is dull-white, and very tough, clinging to the scissors so that a straight cut is almost impossible. Delicate walls divide the interior into several compartments, in all of which are evidences that the caterpillars must have resided for some time. The reason why the creatures make this nest is, that they are hatched towards the end of summer, and in consequence are forced to pass the winter in the larval condition, so that some warm residence is needful for them. It is well known that air is a very bad conductor of heat, and, in consequence, the