Thomas has proved by sections of the wing of Danais, etc., that the androconia arise from glands situated in a fold of the wing (Fig. 230), and he states that the material elaborated by the local glands, and distributed upon the surface of the wing by the androconia, is that which gives to many of the Lepidoptera their characteristic odor. On comparing these “glands,” it is evident that they are groups of specialized formative cells of Semper (trichogens), which secrete an odorous fluid, issuing perhaps from extremely fine pore-canals at the ends of the androconia. They thus correspond to the glandular hairs, poison-hairs, and spines of caterpillars, the formative cells of which contain either a clear lymph or poison. LITERATURE _a._ Hairs, bristles, cleaning spines, calcaria, combs, etc. =Leydig, Franz.= Zum feineren Bau der Arthropoden. (Müller’s Archiv f. Anat. und Phys., 1855, pp. 376–480.) =Fobel, Auguste.= Les fourmis de la Suisse. Bâle, 1874. =Saunders, Edward.= Remarks on the hairs of some of our British Hymenoptera. (Trans. Ent. Soc. London, 1878, pp. 169–171.) =Perez, J.= Notes d’apiculture. (Bull. Soc. d’Apic. de la Gironde, Bordeaux, 1882.) =Osten Sacken, C. R. von.= An essay on comparative chætotaxy, or the arrangement of characteristic bristles of Diptera. (Trans. Ent. Soc. London, 1884, pp. 497–517.) —— Preliminary notice of a subdivision of the suborder Orthorrhapha Brachycera (Diptera) on chætotactic principles. (Berlin Ent. Zeitschr., 1896, pp. 365–373.) =Janet, Charles.= Études sur les fourmis. 8^e Note. Sur l’organe de nettoyage tibio-tarsien de _Myrmica rubra_. (Ann. Soc. Ent. France, 1895, pp. 691–704, 6 Figs.) See also J. B. Smith’s Economic Entomology, 1896, hairs of bees. Also the writings of De Geer, Huber, Fenger, Mayr, Forel, Canestrini, and Berlese (1880); Dahl, Cheshire, etc. _b._ Glandular and poisonous setæ and spines =Ratzeburg, J. Th. Ch.= Ueber entomologische Krankheiten. (Stettin Ent. Zeit., 1846, vii, pp. 35–41.) =Zeller, P. C.= Revision der Pterophoriden. (Linnæa Ent., vi, pp. 319–416, 1852, at p. 356 speaks of “Drüsenhärchen.”) =Dimmock, George.= On some glands which open externally on insects. (Psyche, iii, pp. 387–401, 1882.) =Goossens, Th.= Des chenilles urticants. (Ann. Soc. Ent. France, 1881, pp. 231–236.) Des chenilles vésicants. (Ibid., 1886, pp. 461–464.) =Packard, A. S.= Notes on some points in the external structure and phylogeny of insects. (Proc. Boston Soc. Nat. Hist., xxv, 1890, pp. 83–114, 2 Pls.) —— A study of the transformations and anatomy of _Lagoa crispata_, a bombycine moth. (Proc. Amer. Phil. Soc., xxxii, pp. 275–292, 7 Pls., 1894.)