mens being as large as the figure, if not larger, while others are no bigger than gnats. The mode in which the Pimplas deposit their eggs is well told by Mr. Westwood :~

‘May 29, 1830, I observed a Pimpla, with the ovipositor almost as long as the body, in the act of oviposition in a dry paling, which had been much perforated, and out of which I had just dug a black Pemphredon. The part in which the ovipositor was introduced appeared to be quite solid. (Eeaumur represents his specimens as inserting their ovipositors in a circular patch of dried clay, used to stop up the entrance to the nest of the intended victim.) There were several very minute blackish spots, as they seemed to be, close to the place where the ovipositor was inserted, and which were probably other places of insertion of the ovipositor.

‘ When first observed, the insect had introduced about half the terebra into the post, the part remaining uninserted being at right angles with the body, the sheaths being curved and their tips being brought to the place of insertion, thus evidently strengthening the terebra in its operations. The abdomen was at this time alternately turned from left to right, and vice versa, whereby a bradawl kind of motion was given to the terebra, enabling it to penetrate the wood to a greater depth. It then alternately partially withdrew and replunged the terebra into the hole thus made, as though in the act of passing an egg or eggs, standing all this while on the tips of the tarsi. On cutting, however, into the post, I was not able to discover any lignivorous larva, finding only a channel of fine, white pulverised wood, which had been made by a previous occupier of the tube.’

Some further details of this insect are given on Woodcut XXXI. Fig. h shows the lateral view of the female abdomen in a fresh insect, and c is the same portion of a dried specimen. Fig. d shows the abdomen as seen from beneath, and Fig. e shows the end of the male abdomen.

Some of the Ichneuroons have wonderfully long and slender ovipositors. One of them, Rhyssa persuasona, is shown on Plate X. Fig. 5, one being seen in the act of depositing her eggs, and the other to be flying. In this genus the abdomen is without a footstalk, long, convex, and furnished with a very

Plate X. Parasitic Hymenoptera.

Pezornachus zonatiis and nests of Spider. 2. Pezornachus fasciatus. 3. Trogus atropos. 4. Ehyssa persuasoria. 5. Rhyssa depositing eggs. 6. Chelonus ociilator (rather magnified).

Caterpillar of Death’s Head Moth. In Middle. Plants : — Willow. Above. Dog-grass {Cy7iosurus). In Middle, with mud-nests of Spider. Wood Sorrel (Oxalts acetosella). Below.

i ;j j J

-long ovipositor. The present species is nearly as vai'iable in size as the Pimpla which has just been described. Its colour •is black, diversified by bright yellow spots along the sides of the thorax and body, as seen in the illustration. Like some other Ichneumons with very long ovipositors, it is parasitic on larvae which burrow into solid wood.

On Plate X. Fig. 6, is seen a magnified figure of a curious insect, called Ckelonus-oculator. In this genus there are two submarginal cells, the ^first of which is not complete. The eyes are hairy. This species is not a common insect, and seems to be a local and recurrent one. Mr. F. Smith tells me that in one day he took more than fifty specimens, by sweeping the grass on the top of the cliffs at Lowestoft, and that he has hardly ever seen as many since as he took on that one occasion. The colour of the insect is black, some specimens, particularly the males, having a yellow band across the abdomen. It is, however, very variable both in size and* colour. The economy of this insect is very curious, and is not thoroughly cleared up.

On Woodcut XXXII. Fig. 1, may be seen a much magnified illustration of a very small but singularly useful insect— so useful, indeed, that without its aid we should scarcely be able to raise a single cabbage. This is called Microgaster glomeratus. In this genus the eyes are hairy, the antennae long and consisting of eighteen joints. The present species is darkbodied, and its wings are translucent, but, when viewed through the microscope, are wonderfully beautiful, glittering with every hue of the rainbow as the light plays over them.

This^ little insect is parasitic on the common Cabbage-caterpillar, i.e. the larva of the Oreat Cabbage White Butterfly and so rapidly does it multiply that, after watching its progress from the larva to maturity, it seems strange that a single Cabbage White Butterfly should be found in the counky Owing to its numbers, the young entomologist will find this^ insect an admirable one for experiments. If a hundred Cab bage-caterpillars be captured, there will be only one or two' which do not contain the larv® of the Microgaster. Their rela tive size in proportion to the caterpillar is shown at Fig c o? the same Woodcut, but neither their numbers nor their position

If a ‘stung’ caterpillar be carefully dissected, so that the skin

18 removed from the body, the space between the digestive

organs and the skin, which ought to be occupied by a layer

of fat, IS found to be literally stuffed with the tiny white

grubs of the Microgaster.

The fatty substance on which these larvas feed is intended

Microgaster glomeratns. 2. Mymar pulchellus. 3. Teleas elatior. 4. Cleonymns maculipenuis. a. Teleas, antenna, female. b. Do., antenna, male. c. Microgaster, larva in caterpillar of cabbage-butterfly, d, Microgaster alvearius, cocoons.

as material from which the future butterfly is to be evolved. But, as it is almost entirely consumed by these internal foes, the insect seldom has sufficient strength to effect its change into the pupa — much less into the butterfly. Just in proportion as the fat decreases, the Ichneumon larvas increase, so that to the eye the caterpillar looks quite plump and healthy, when it is in reality absolutely emaciated. Yet the presence of these

parasites seems to have no effect on the caterpillar, who eats as

voraciously and. grows as rapidly as if it were free from its internal devourers.

All, therefore, goes on apparently well, until the time when the insect ought to make its change to the pupal state, being full-fed, or at least as full-fed as it can be. But the larvae of the Microgaster are full-fed too ; and, just before the caterpillar changes into the pupa, they biu'st through it in all directions and leave it to die. Grenerally, it dies so soon that its shrivelled body remains in the midst of its enemies, and it seldom has sufficient strength to move more than a few inches away from them. The Ichneumon larvae immediately begin to spin for themselves little yellow cocoons of silk, very much resembling that of a silkworm, and clustered closely together. I have noticed that those which come from one caterpillar generally congregate into two totally distinct clusters, those which occupied the different sides of the caterpillar remaining neighbours as before. The specific name of glomeratus^ or clustered, refers to this habit.

Almost any number of these cocoon-clusters may be obtained fiom the walls, posts, or palings that adjoin kitchen-gardens; and the tree-trunks of the garden are equally prolific in them. If a cocoon be cut open with a very fine pair of scissors, the pupa may be seen lying in its silken cell, and, with a little care, the whole progress of the insect can be watched, from the larva to the pupa. I have dissected great numbers of cabbage caterpillars for the sake of observing the curious relationship between the caterpillar and the Ichneumon, and the the latter insect. development of

There is a closely alHed species, named Microgaster alvearius, which in many things resembles the preceding species, but which has a different method of arranging its cocoons. Those of the preceding insect are arranged quite at random, or indeed can scarcely be said to be arranged at all, the larvae spinning their cocoons without any reference as to the position in which they might happen to be at the time. But, the present insects when they are about to change into the pupal state, arranoe tlieir cocoons side by side with the greatest regularity, as seen at Fig. d on Woodcut XXXII. Masses of these pretty cocoons

can be found adhering to twigs, and from them the insects can be procured in considerable numbers. I find, on examining a series of these cocoon-masses, that the number of individual cocoons is somewhere about one hundred and fifty.

When the pupa changes to its perfect form, it gnaws a round hole at one end of the cocoon, so as to cut out a sort of lid, by raising which it can escape. Very often, the inverted lid is left in the cut end of the cocoon and closes it. The average length of the cocoon-cluster is nine-tenths of an inch, its width nearly a quarter of an inch, and the depth of cell one-tenth of an inch. The insects are pale and shining yellow, with the upper part of the abdomen and end of the thorax black.

We now come to the great family of the Chalcididae. These insects are parasitic, are for the most part exceedingly small, and many are very tiny indeed. The head is transverse, the eyes set on the sides, and the antennae are short. The upper pair of wings are almost without nervur'es, though the course of one or two can be traced by careful examination with a microscope. The lower wings have only a single nervure. They are parasitic insects, many of them being actually parasitic upon other parasites, and some depositing their eggs in various galls, where they feed upon the rightful inhabitants, and in due time make their appearance, to the great perplexity of practical entomologists who have kept the galls for the purpose of rearing the particular Grail-flies which belong to them.

One of these insects, called Cleonymus maculipennis or depressus^ is shown on Woodcut XXXII. Fig. 4.

It is a very pretty little insect, the colour being a deep metallic blue, changing to green and .pink- according to the variation of the light. The antennae are red, tipped with black, and the abdomen is flattened, a characteristic which gained for it the name of depressus. The wings are prettily mottled with brown, as seen in the illustration. Mr. F. Smith says that he has often seen it running quickly about posts and rails, engaged in prying into every orifice, probably for the busily some wood-boring insect, in whose body it sake of detecting can lay its eggs.

In this genus the thorax is rather long and egg-shaped, the

antennae have eleven joints, the second of vehich is longer

than the foui’th. The ovipositor is not protruded.

We now pass to the family of Proctotrupidae. This family

comprises some of the smallest known Hymenoptera ; indeed, many of them are so exceedingly minute that they can only be seen by the aid of a lens. In these insects the hind wings have no nervui'es at all, while those of the fore wings are but few in number. The antennae have the first joint larger than the others, and in some species they are as long as the body.

One of the larger species is given on Woodcut XXXII. Fig. 3. Its name is Teleaa elatior. In this genus the legs are formed for jumping, the abdomen has a footstalk, and the antennae have twelve joints, and are hairy in the male. The male antenna is shown at Fig. 6, that of the female at Fig. a. The colour of this species is very deep black-blue, and the wings are very iridescent.

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