BIBLIOGRAPHY.--The literature of several special families of the Hymenoptera will be found under the articles ANT, BEE, ICHNEUMON-FLY, WASP, &c., referred to above. Among earlier students on structure may be mentioned P. A. Latreille, _Familles naturelles du règne animal_ (Paris, 1825), who recognized the nature of the "median segment." C. Gerstaecker (_Arch. f. Naturg._ xx., 1867) and F. Brauer (_Sitzb. K. Akad. Wiss. Wien._ lxxxv., 1883) should also be consulted on this subject. For internal anatomy, specially the digestive organs, see L. Dufour, _Mém. savants étrangers_, vii. (1841), and _Ann. Sci. Nat. Zool._ (4), i. 1854. For nervous system H. Viallanes, _Ann. Sci. Nat. Zool._ (7), ii. iv. 1886-1887, and F. C. Kenyon, _Journ. Comp. Neurol._ vi., 1896. For poison and other glands, see L. Bordas, _Ann. Sci. Nat. Zool._ (7) xix., 1895. For the sting and ovipositor H. Dewitz, _Zeits. wiss. Zool._ xxv., 1874, xxviii., 1877, and F. Zander, _ib._ lxvi., 1899. For male genital armature S. A. Peytoureau, _Morphologie de l'armure génitale des insectes_ (Bordeaux, 1895), and E. Zander, Zeits. wiss. Zool. lxvii., 1900. The systematic student of Hymenoptera is greatly helped by C. G. de Dalla Torre's _Catalogus Hymenopterorum_ (10 vols., Leipzig, 1893-1902). For general classifications see F. W. Konow, _Entom. Nachtr._ (1897), and W. H. Ashmead, _Proc. U.S. Nat. Mus._ xxiii., 1901; the latter paper deals also especially with the Ichneumonoidea of the globe. For habits and life histories of Hymenoptera see J. Lubbock (Lord Avebury), _Ants, Bees and Wasps_ (9th ed., London, 1889); C. Janet, _Études sur les fourmis, les guêpes et les abeilles_ (Paris, &c., 1893 and onwards); and G. W. and E. G. Peckham, _Instincts and Habits of Solitary Wasps_ (Madison, Wis. U.S.A., 1898). Monographs of most of the families of British Hymenoptera have now been published. For saw-flies and gall-flies, see P. Cameron's _British Phytophagous Hymenoptera_ (4 vols., London, _Roy. Soc._, 1882-1893). For Ichneumonoidea, C. Morley's _Ichneumons of Great Britain_ (Plymouth, 1903, &c.), and T. A. Marshall's "British Braconidae," _Trans. Entom. Soc._, 1885-1899. The smaller parasitic Hymenoptera have been neglected in this country since A. H. Haliday's classical papers _Entom. Mag._ i.-v., (1833-1838) but Ashmead's "North American Proctotrypidae" (_Bull. U.S. Nat. Mus._ xlv., 1893) is valuable for the European student. For the Fossores, wasps, ants and bees see E. Saunders, _Hymenoptera Aculeata of the British Islands_ (London, 1896). Exhaustive references to general systematic works will be found in de Dalla Torre's _Catalogue_ mentioned above. Of special value to English students are C. T. Bingham's _Fauna of British India_, "Hymenoptera" (London, 1897 and onwards), and P. Cameron's volumes on Hymenoptera in the _Biologia Centrali-Americana_. F. Smith's _Catalogues of Hymenoptera in the