Embryology.--F. Blochmann (_Morph. Jahrb._ xii., 1887); A. Kovalevsky (_Mem. Acad. St-Petersbourg_, xvi., 1871; _Zeits. wiss. Zool._ xlv., 1887); V. Graber (_Denksch. Akad. Wissens., Wien_, lvi., 1889); K. Heider, _Die Embryonalentwicklung von Hydrophilus piceus_ (Jena, 1889); W. M. Wheeler (_Journ. Morph._ iii., viii., 1889-1893); E. Korschelt and K. Heider, _Handbook of the Comparative Embryology of Invertebrates_ (trans. M. Bernard), (vol. iii., London, 1899); R. Heymons, _Die Embryonalentwicklung von Dermapteren und Orthopteren_ (Jena, 1895) (also _Zeits. wiss. Zool._ liii., 1891, lxii., 1897; _Anhang zu den Abhandl. K. Akad. d. Wissens., Berlin_, 1896); A. Lecaillon (_Arch. d'anat. micr._ ii., 1898); J. Carriere and O. Burger (_Abhandl. K. Leop.-Carol. Akad._ lxix., 1897); K. Escherich (ibid. lxxvii., 1901); F. Schwangart (_Zeits. wiss. Zool._ lxxvi., 1904); R. Ritter (_ib._ li., 1890); E. Metchnikoff (_ib._ xvi., 1866); H. Uzel (_Zool. Anz._ xx., 1897); J. W. Folsom (_Bull. Mus. Comp. Zool. Harvard_., xxxvi., 1900). Parthenogenesis and Paedogenesis.--T. H. Huxley (_Trans. Linn. Soc._ xxii., 1858); R. Leuckart, _Zur Kenntnis des Generationswechsels und der Parthogenesis bei den Insekten_ (Frankfurt, 1858); N. Wagner (_Zeits. wiss. Zool._ xv., 1865); L. F. Henneguy (_Bull. Soc. Philomath._ [9], i. 1899); A. Petrunkevich (_Zool. Jahrb. Anat._ xiv., xvii., 1901-1903); P. Marchal (_Arch. zool. exp. et gen._ [4], ii., 1904); L. Doncaster (_Quart. Journ. Micr. Sci._ xlix., li., 1906-1907). Growth and Metamorphosis.--A. Weismann (_Zeits. wiss. Zool._ xiii., xiv., 1863-1864); F. Brauer (_Verh. zool.-bot. Gesellsch., Wien_, xix., 1869); Sir J. Lubbock (Lord Avebury), _Origin and Metamorphosis of Insects_ (London, 1874); L. C. Miall (_Nature_, liii., 1895); L. C. Miall and A. R. Hammond, _Structure and Life-history of the Harlequin-fly_ (Oxford, 1900); J. Gonin (_Bull. Soc. Vaud. Sci. Nat._ xxx., 1894); C. de Bruyne (_Arch. de biol._ xv. (1898); D. Sharp (_Proc. Inter. Zool. Congress_, 1898); E. B. Poulton (_Trans. Linn. Soc._ v., 1891); T. A. Chapman (_Trans. Ent. Soc._, 1893). Classification.--F. Brauer (_S. B. Akad. Wiss., Wien_, xci., 1885); A. S. Packard (_Amer. Nat._ xx.; 1886); C. Borner, A. Handlirsch, F. Klapalek (_Zool. Anz._ xxvii., 1904); G. Enderlein (_Zool. Anz._ xxvi., 1903). Palaeontology.--S. H. Scudder, in Zittel's _Palaeontology_ (French trans., vol. ii., Paris, 1887, and Eng. trans., vol. i., London, 1900); C. Brongniart, _Insectes fossiles des temps primaires_ (St-Etienne, 1894); A. Handlirsch, _Die fossilen Insekten und die Phylogenie der rezenten Formen_ (Leipzig, 1906).