Just as the hymenoptera are chief among the pensiles and the builders, so are they chief among the Social Insects, and the species which may be placed in this group are so numerous, that it will only be possible to make a selection of a few, which seem more interesting than the others.

IN the British Museum there are some very remarkable nests made by hymenopterous insects belonging to the genus Polybia, several of which are drawn in the accompanying illustration. As it was desirable to include more than one specimen, the figures are necessarily much reduced in size. Neither the nests nor the insects, however, are of large dimensions, and the former are so sombre in colour as well as small in size, that they would not of themselves attract any attention. Their nests, however,

are extremely interesting, as may be seen from the examples which are figured in the illustration.

On the left hand may be seen a nearly spherical nest, which is evidently hollow, and has cells both on the outside and within the cover. These cells are not placed vertically, with their mouths downward, like those of the wasp and hornet, nor horizontally like those of the bee, but are set with their mouths radiating from the centre of the nest. Moreover, there is another curious circumstance connected with the nest. If it were to be opened, it would be seen to be composed of several concentric layers, very much like those ivory puzzle-balls which the Chinese make so beautifully.

The method by which the nest is formed is very simple, though not one that is usually seen among the hymenoptera. The layers of combs are made like hollow spheres, the mouths of the cells being outwards, and as soon as a layer is completed, the insects protect it from the weather by a cover of the same material as is used for the construction of the cells. When they require to make a fresh layer of cells, they do not enlarge the cover, as is the case with the wasp and hornet, but place the new cells upon the surface of the cover, and make a fresh cover as soon as the comb is completed. Thus the nest increases by the addition of concentric layers, composed alternately of comb and cover.

In the nest which is in the British Museum, the insects have commenced several patches of comb on the outside of the cover, and one such patch is shown in the illustration.

On the right of the globular nest is another curious structure, also made by insects of the same genus, and having a kind of similarity in its aspect. This nest, however, is very much longer in proportion to its width, and being fixed throughout its length to a leaf, is not so plainly visible as the last mentioned specimen. Indeed, when the leaf has withered, as is the case with the object from which the drawing was made, the dull brown of the nest coincides so completely with the colour of the faded leaf, that many persons would overlook it unless their attention were specially drawn towards it.

On the extreme right of the illustration, and in the upper corner, is seen a nest which is also the work of insects belonging to the genus Polybia, and it is pendent from a bough, like the habitation of the Chartergus and other pensile hymenoptera.

In the same collection there are many more specimens of social nests formed by insects belonging to this genus, two cases being quite filled with them. One is attached to the bark of a tree, and resembles it so closely that it seems to be made of the same substance, this similarity of aspect being evidently intended as a preservative against the attacks of birds and other insectloving creatures, which would break up the nest, and eat the immature and tender grubs. Most of the nests are fixed to leaves, and are different forms, according to the species which made them. They are mostly fixed to the under sides of the leaf, so that the weight causes the leaf to bend and to form a natural roof above them. The shape of the nest seems to depend much on the character of the plant to which it is fixed. Those that are fastened to reeds are long and slender, and generally much narrower than the sword-shaped leaf on which they rest. Others, which are fastened to short and broad leaves, adapt themselves so closely to the shape of the leaf, that, if removed, they would enable any one to conjecture the form of the leaf upon which they had been fixed.

One such nest is very remarkable. In general form it bears a singular resemblance to the nest of the fairy martin, which is figured at page 313, though its materials are entirely different. The nest is flask-shaped, and its base is fastened to a leaf which it almost covers. The body of the nest is oval, and the entrance, which is small, is placed at the end of a well-marked neck. The shell of the nest is extremely thin, not in the least like the loose, papery structure of an ordinary wasp-nest, nor the pasteboard-like material which defends the nest of the Chartergus. It is rather fragile, and in thickness is almost double that of the paper on which this account is printed.

The name of the species which builds this curious nest is Polybia sedula, and the specimen was brought from Brazil.

FOR the reasons which have been given at the beginning of this chapter, the HIVE BEE has been reckoned among the Social Insects.

The Bee has always been one of the most interesting insects to mankind, on account of the direct benefit which it confers upon the human race. There are many other insects which are in reality quite as useful to us, and indeed are indispensable,

but which we neglect because we are ignorant of their labours. The Bee, however, furnishes two powerful and tangible arguments in its favour-namely, honey and wax-and is sure, therefore, to enlist our sympathies in its behalf.

Independently, however, of these claims to our notice, if the Bee never made an ounce of honey-if the wax were as useless to us as wasp-comb-if the insect were a mere stinging creature, with a tetchy temper, it would still deserve our admiration, on account of the wonderful manner in which it constructs its social home, and the method by which that home is regulated.

The accompanying illustration shows the lower part of the interior of a hive, which is supposed to be viewed through a plate of glass set in the back. When the hive is in full operation, the combs are so crowded with Bees that their structure

can hardly be seen; but in the illustration the Bees are supposed to have gone away, with the exception of one individual.

I need not in this place repeat the well-known facts respecting the constitution of the Bees, nor describe the duties of the Queen, Drone, and Worker Bees. Suffice it to say, that the former is the mother as well as the queen of the hive; that the workers are undeveloped females, which are properly called neuters; and that the drones are males, which do no work, and have no stings.

In the illustration, the Queen Bee is seen walking over the combs, and in this position she exhibits the peculiarities of form which distinguish her from her subjects, and which enables an experienced eye to detect her at once amid a crowd of workers. In the Queen Bee, the abdomen is long in proportion to its width, and the wings slightly cross each other when closed; the latter being a very conspicuous badge of sovereignty. The drones are easily distinguished by their generally larger size, their larger eyes, and the wide, blunt, and rounded abdomen.

The lower part of the comb, in the foreground, is formed of cells which are closed at their mouth, and which do not show the hexagonal shape as well as those which are yet empty. Some of the empty cells are shown above, and the Queen Bee is represented as making her way towards them.

There are three kinds of cell in a hive; namely, the workercell, the drone-cell, and the royal-cell. Of these, the two former are hexagonal, but can easily be distinguished by the greater size of the drone-cell; while the royal-cell is totally unlike the nursery of a subject, whether drone or worker, and is almost always placed on the edge of a comb. One of these cells is shown in the illustration, and may be seen on the edge of the comb in the foreground. It is very much larger than an ordinary cell, and is built with a lavish expenditure of wax that affords a curious contrast with the rigid economy observed in the structure of the other cells. The difference of size between the worker and drone-cells is shown in the central comb, where the workercells are seen below, and the drone-cells above.

The little grub which is placed in the royal cell is not fed with the same food which is supplied to the other Bees, but lives upon an entirely different diet, and which is, apparently, of a more stimulating character; and it is now well known, that if a