The name _hypopharynx_ was first proposed by Savigny in 1816, who, after naming the membranous plate which has for its base the upper side of the pharynx, the _epipharynx_, remarks: “Dans quelques genres, notamment dans les Eucères, le bord inférieur de ce même pharynx donne naissance à un autre appendice plus solide que le précédent, et qui s’emboîte avec lui. Je donnerai à ce dernier le nom de _langue_ ou d’_hypopharynx_. Voilà donc la bouche des Hyménoptères composée de quatre organes impaires, sans y comprendre la ganache ou le menton; savoir, la lèvre supérieure, l’épipharynx, l’hypopharynx, et la lèvre inférieure, et de deux organes paires, les mandibules et les mâchoires.” As stated by Dimmock: “The hypopharynx is usually present in Diptera (according to Menzbier absent in Sargus), and contains a tube, opening by a channel on its upper surface; this channel extends back, more or less, from the tip, and is the outlet for the salivary secretion. The tip of the hypopharynx may be naked and used as a lance (Hæmatopota, according to Menzbier), or may be hairy (Musca). The upper side of the base of the hypopharynx is continuous with the lower wall of the pharynx; its under surface may entirely coalesce with the labium (Culex, male), may join the labium more or less, anterior to the month (Musca), or, if either mandibles or maxillæ are present, its base may join them (Culex, female).” (p. 43.) [Illustration: FIG. 69.—Section of head of _Machilis maritima_: _hyp_, hypopharynx; _lbr_, labrum; _t_, tentorium; _ph_, room in which the mandibles move on each other; _p_, paraglossa; _mx_, labium; _sd_, salivary duct; _s.gl_, salivary gland. _oe_, œsophagus.—After Oudemans. ] We will now briefly describe the lingua, first of the mandibulate or biting insects, and then its specialized form, the hypopharynx of the haustellate and lapping insects. The lingua (hypopharynx) exists in perhaps its most generalized condition in the Thysanura (Fig. 69), where it forms a soft projection, having the same relations as in Anabrus and other Orthoptera.[17] In the cockroach (Fig. 70), as stated by Miall and Denny, the lingua is a chitinous fold of the oral integument situated in front of the labium, and lying in the cavity of the mouth. The common duct of the salivary glands enters the lingua, and opens on its hinder surface. The lingua is supported by a chitinous skeleton (Figs. 70, _B_; 82, _shp_). “The thin chitinous surface of the lingua is hairy, like other parts of the mouth, and stiffened by special chitinous rods or bands.” (Miall and Denny.) [Illustration: FIG. 70.—Hypopharynx of _Periplaneta orientalis_; the arrow points out of the opening of the salivary duct: _A_, origin of salivary duct. _B_, side view. _C_, front view.—After Miall and Denny. ]