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Show 82 INSECTA. illre and a lip • at the extremity of the latter is a fusus for the tran's mission of' the silky material that is to be employe d.1 0 con-structing the cocoon of the nymph. Some feed on vegetable substances, while others, alw~ys destitute of feet devour the carcases of Insects together With ' their larvre, nymphs, and even eggs. To remedy their want of locomotive powers, the mot~er furnishes them with provisions, sometimes by transport~ng aliment into the nests she has prepared for th.,em, .whiCh are frequently constructed with so much art as to excite our wonder and surprise, and sometimes by depositing h~r eggs in the l>ody of the Iarvre and nymphs of Insects, on whiCh her · progeny are to feed. Other larvre of Hymenoptera, alsp destitute of feet, require more elaborated and frequently renewed supplies of aliment, both vegetable and animal. These are reared in common by neuters forming communities, of which they have the sole care; their labours and mode of life will always continue to excite our admiration and astonishment. Almost all Hymenopterous Insects, in their perfect state, live on flowers and are usually most abundant in southern eli· mates. Their period of life, from their birth to their ultimate metamorphosis, is limited to a year. M. Leon Dufour in his Memoire sur l' .llnatomie des Sea· lies-Journ. de Phys., Sept. 1828-remarks, that in all the Hymenoptera submitted to his scalpel, the trachere are a de· gree more perfect than those of the other orders of Insects; that instead of being formed by cylindrical and elastic vessels, the diameter of which decreases by their successive divisions, they present constant dilatations, decided vesicles favourable to the greater or less permanence of air, and susceptible of extension and diminution, according to the quantity of that fluid admitted. On each side of the base of the abdomen may be found one of these vesicles; it is large, oval, and of a dead ]acteous-white, giving off here and theJ•e vascular trachere which at·e distributed among the adjacent organs. In penetrating into the thorax it is tStrangulated, dilates again, HYMENOPTERA. , 83 an~ insensibly degenerates into a tube, the subd' .. winch are lost in the head. Behind these two bdiVI~Ionls of sicJes th f . . a omina ve- ' e organ o respuatwn continues on in tw fir~ tubes, giving off an infinity of ramous branches and ~ I ~rm con flue t th ' ecommg . n nea~ e anus. In the Xy1ocopre and Bombi the anterwr superwr surface of each of the two great abd '. 1 ve.s icles I· s. f urm·s h e d W·i t h a cylindrical, elastic, greyish obmo1dn a ~ut adhermg ~hroughout its length in the Xylocopre, and fr~; m the Bombi. M. Dufour· thinks that this body w·h· h . dI' rec t e d toward s the I· nserti.O n of the w· h ' IC .I S tJ d . Ing, as some part In . le pro uctwn of the humming noise made by these Insects masmuch as that sound may continue after the wings h ' been taken off. ave I wi11 divide this order into two se~tions. The first, or that of the TEREBRANTIA, is characterized by th~ ~resen.ce of an ovipositor in the females. I divide this section into two great families. FAMILY I. SECURIFERA. Ou~ first family is distinguished from the followin ones b a sessile abdomen, or the base of wh· h . . . d g Y throughout its whole th' k Ic 18 JOme to the thorax ;, tion of it and to h Ic ness, that _seems to be a continua-ave no separate motwn(l ). The females are prov'd d · h . . commonly serrated and ~;. h Wit anlovipositor that is most 't i . ' Ic not on y enables them to de posi. t:heir eggs, but likewise to prepare a place ~or th . - ception Th 1 e1r re-quent] y. o'ther: t~:tv::earaelwaysbhave six squamous feet, and fre-mem ranous. (1) The segment, bearing the inf, . . . one or the first of •he bd erwr wmgs, Is separated from the following ot h er segments the~'n- foail omen. , by a tra. ns verse I· nC·i sure ot· articulation. The lation. ow unmterruptedly, and without any particular stra.ngu. |
