Some other hymenoptera may be mentioned: for example, the _Evaniadæ_, the _Chalcididæ_, as well as the _Tachinariæ_, which are remarkable for this kind of life. At the moment when the mining hymenoptera introduce into their hiding-places the insects which they have seized, and which they destine for their young ones, the Tachinariæ introduce themselves by stealth, and lay their eggs on these provisions. Each kind of tachinariæ attaches itself to a particular insect. There is one essential difference between them and ichneumons, that the females of the latter perforate the skin of their victims with a pointed instrument, and cause their eggs to penetrate to the interior of the entrails; while the mother tachinæ, less cruel, are contented to lay their eggs on the surface of the skin, and leave to the larva the care of penetrating into the interior. In the department of the Aube, not far from Lezignan, the Tithymalis (_Euphorbia helioscopa_) grows abundantly, and the natural guest of this plant is a Sphynx. While this sphynx is still a caterpillar, a dipterous tachinaria takes possession of it to feed her young ones. 167 For this purpose the fly establishes itself upon the back of the caterpillar, and mounted thus, without the caterpillar's suspecting the least in the world the danger that it runs, the fly inserts her larvæ to the number of ten or twelve. When she has thus deposited these, the fly goes to seek another caterpillar, like the cuckoo in search of a fresh nest every time that she lays an egg. The young flies, left to themselves, pierce the skin of their host, and all take their place at the banquet, says Mons. Barthelemy. After three moults the fly is completely developed, it devours the interior of the larvæ which has nourished it, pierces the skin, and the dead body of its host, which might have been its tomb, becomes, on the contrary, its cradle. While not far off from the remains of its feast, its own skin hardens till it becomes a veritable shell, and the parasitical insect awakes, furnished with wings, ready to recommence, after a minute devoted to love, the circle in which pass the unvarying phases of its evolution. The female of the _Scolia_ attacks the larva of the large scarabæus (_Oryctes nasicornis_), which is found in tan, and pierces it with its ovipositor at the same time that it deposits an egg in the body of the gigantic larva. The larva which will proceed from the egg will suck up the fluid parts of the Oryctes while on the grass, and the skin of its victim will serve in the spring as a cradle for its transformation into a nymph. Scolietes also attack the large oryctes which destroys the cocoa-nut trees of the Seychelles Islands. It is the same with a large species found in Madagascar.