Fig. 192.—Base of the ovipositor of Locusta viridissima seen from beneath: c′, sheath, or outer and lower pair of stylets turned to one side to show the others; b′, upper and inner pair; b″, third or innermost, smallest pair of stylets. A, the same on one side, in section. The shaded parts show the muscular attachments. The muscles which extend the apparatus and are attached to ν, δ, and η, as also the membranes which unite the pieces from η; to γ with each other and the body, are removed, so that only the chitinous parts remain.—After Dewitz.
Fig. 193.—Development of the sting in Bombus: A, a, 1st pair on 8th sternite; b, 2d inner pair forming the darts; c, outer pair. B-E, more advanced stages. F, x, y, z, three pairs of tubercles, the germs of the male organs.
Fig. 194.—Sting of bee × 30 times: A, sting separated from its muscles; ps, poison sac; pg, poison gland; 5th g, 5th abdominal ganglion; n, n, nerves; e, external thin membrane joining sting to last abdominal segment; i, k, l, and i′, k′, l′, levers to move the darts; sh, sheath; v, vulva; p, sting-palpus or feeler, with tactile hairs and nerves. B and C, sections through the darts and sheath, × 300 times: sh, sheath; d, darts; b, barbs; p, poison-channel. D, end of a dart, × 200: o, o, openings for poison to escape into the wound.—After Cheshire.
Fig. 195.—Details of sting of bee: E, darts, sheath, and valves; pb, poison-bag duct; fo, fork; s, slide piece; va, valve; b, barbs. F, terminal abdominal segments; w, worker’s sting; q, queen’s sting; r, r′, anal plate; G, sting entering skin; sh, sheath; a, b, c, positions in first, second, and third thrusts with the sting. H, portion of poison gland, × 300; cn, cell nucleus; n, nerve; g, ganglionic cell. I, portion of the poison gland, cells removed; cd, central duct; d, individual small ducts; pr, tunica propria. K, gland of Formica rufa; cd, central duct; d, small ducts; sc, secreting cells. L, valve and support; t, trachea; va, valve; tr, truss or valve-prop.—After Cheshire.
Fig. 196.—A, rudimentary ovipositor of nymph of Æschna. B, the corresponding ♂ structures; a, enlarged. C, ovipositor of nymph of Agrion; d, gill.