[46] Zeits. f. wiss. Zool., Bd. XVI., pl. vii., fig. 33.
[47] Insekten, Vol. II., p. 508.
[48] Anat. Invert. Animals, p. 398.
[49] Professor Huxley has proposed to call the attached base hypopharynx, and the free tip lingua.
[50] Professor J. Wood-Mason points out that in Machilis (one of the Thysanura) the mandible shows signs of segmentation, while the apical portion is deeply divided into an inner and an outer half. Ripe embryos of Panesthia (Blatta) javanica are said to exhibit folds which indicate the consolidation of the mandible out of separate joints, while the cutting and crushing portions of the edge are divided by a “sutural mark,” which may correspond to the line of junction of the divisions of a biramous appendage (Trans. Ent. Soc., 1879, pt. 2, p. 145).
[51] The homology of the labium with the first pair of maxillæ is in no other Insects so distinct as in the Orthoptera.
[52] Rosenthal, Ueb. d. Geruchsinn der Insekten. Arch. f. Phys. Reil u. Autenrieth, Bd. X. (1811). Hauser, Zeits. f. wiss. Zool., Bd. XXXIV. (1880).
[53] Mém. Acad. Roy. de Belgique, Tom. XLI. (1874). Prof. Plateau’s writings will often be referred to in these pages. We owe to him the most important researches into the physiology of Invertebrates which have appeared for many years.
[54] Exp. sur le Rôle des Palpes chez les Arthropodes Maxillés. Pt. I. Bull. Soc. Zool. de France, Tom. X. (1885).
[55] Leydig, Taf. z. vergl. Anat., pl. x., fig. 3. Hauser, Zeits. f. wiss. Zool., Bd. XXXIV., p. 386. Jobert has figured the sensory organs of the maxillary palps of the Mole-cricket (Ann. Sci. Nat., 1872), and Forel similar organs in Ants (Bull. Soc. Vaudoise, 1885).