wide a range as the ground-wasps; and this species in particular is confined to certain localities. In the hot summer of 1864, when wasps were everywhere, V. britannica built freely in the neighbourhood of Brighton, to the astonishment of the natives of these parts. But generally, the only tree builder about here is V. sylvestris. In the part of Gloucestershire from which my supplies of wasps and wasps' nests have chiefly been drawn, this is the most common species of tree-wasp, and on it my observations on wasps in general have been chiefly made.

V. sylvestris (Plates VI. XII.) makes a nest which, from a very early period of its existence, has a distinct character. It is not a little bunch of cells at the end of a footstalk, standing in a cup open at the bottom, but the cells and the first envelope are surrounded and shut out from view by a little ball or bell of the most elegant and delicate form.* At the bottom is a round hole, with the edges slightly turned out. Over this are laid one or more separate hoods of the same slight graceful construction, but not reaching so far down as the mouth of the bell in which the second coat terminates. The striking resemblance of this pretty little nest to a toy-bell has added to the many other names of the species that of V. campanaria.†

* V. saxonica, the common tree-wasp at Lausanne, makes its embryo nest in the same elegant pattern. I do not know whether this was the wasp which inflicted the stings which Fabricius Hildanus records, but it has great vitality. A little box of nests which came in a friend's trunk, by a very leisurely journey, supplied me with plenty of live specimens.

This nest is figured in Mr. Knapp's well-known 'Journal of a

Though the little bell disappears in the further development of the nest, yet the complete structure of V. sylvestris retains many of the characters which marked its early stage. We may always notice the broad, even sheets, with their free edges hanging in flounces; and the general lightness and slightness of the covering contrasts with that of the thick, strong nest of V. britannica. Like that, but in a less degree, this species makes its nest pyriform; and it uses the same materials, namely vegetable fibres. The aperture is central. The comb is less hollowed out on the upper surface, and there is less divergence of the lateral cells than we find in V. britannica. Both in the original construction and in subsequent restoration of the nest V. sylvestris is less profusely extravagant of paper than the species last described.

This is, according to her markings and her general habits, a tree-wasp. But no place comes amiss; hollow trees, caves, hedge-banks, and bee-hives are all in their turn honoured by her selection. I think that Gloucestershire is not as congenial to her as the drier parts of England.

V. arborea is not represented in my cabinet, nor in the splendid collection in the British Museum; and I have been unable to obtain a specimen to engrave from any source. Though a ridge about four miles distant from Wakefield, in Yorkshire, and to the

Naturalist,' 3rd ed. p. 333, and Plate VI, fig. 1, its successive stages being very well represented. But the description was written before the Natural History of Wasps had been made clear by Mr. F. Smith, and V. campanaria is set down, p. 332, as a solitary wasp.

North, has been urgently pointed out to any one wishing to obtain a reward for procuring me a nest of this species. The nest is said by its original discoverer to be not unlike that of V. britannica, and to be found in fir-trees. My females were taken in Gloucestershire.

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CHAPTER VIII.

SOCIAL ECONOMY OF WASPS.

HISTORY OF THE COLONY. LARVAL PERIOD. LARVE OF THE HONEYBEE. DEVELOPMENT OF THE BROOD. THEIR SOCIAL LIFE. HABITS OF WASPS. THEIR DISEASES.

IN the last chapter we traced the history of a wasps' nest from its first beginning to its decay and ultimate destruction, and noticed the chief characters by which the work of the different species may be distinguished. We must now, to some extent, go over the same ground again, tracing the history of the living occupants of these nests during the few weeks to which their existence is limited. Much of this information is to be obtained by watching the wasps at work, and by examining the combs after the nests have been taken. But there are other points only to be ascertained by experiments, such as Nature herself may make for us, or which our own studies may suggest. It will be most convenient to keep these branches of the subject separate, that the particular experimental inquiry may supplement the more general survey of the social economy of the

swarm.

The mother-wasp, as we have seen, on awaking from her winter's sleep sets about the construction

of her nest. As fast as each cell takes shape she deposits an egg in it, generally on the inner side of the pouch, and in a corner, firmly glued to the wall. When the cell has been used before it is of course lined with the cocoon of the previous inmate. This makes no difference in the adhesion of the egg, as the glutinous secretion in which it is enveloped penetrates the lining, and fastens the egg through it to the paper wall. But the height of the wall makes a difference as to the position of the egg in the cell, for, as the mother-wasp can only reach to a certain distance with her abdomen, the egg is fixed nearer the mouth of the cell when this is an old one, than when she follows close on the traces of the workers, and deposits the egg before the cell-walls have been built up to their full height.

The egg stands out obliquely from the side of the cell, as a little white speck about half a line long, and in this position it hatches. The larva, however, is not immediately set free from confinement on hatching, for the tail remains fast within the eggshell. On this centre the larva moves freely; it feeds and grows, but cannot get away from the spot on which the egg was laid. The vertical direction of the cells makes this provision necessary, for a moment's consideration will show that, without it, as soon as the larvæ were hatched they would fall out of their cells and die. The embryo wasp has, even at this early period of its existence, a pair of mandibles, distinguished from the pair which it next acquires by the greater length of the central tooth, and mounted on a horny frame very like the bows of a pair of spectacles. These deciduous mandibles are

L