[14]. Miall and Denny in their work on the cockroach, in describing the labium, remark: “The upper edge is applied to the occipital frame, but is neither continuous with that structure nor articulated thereto. By stripping off the labium upwards it may be seen that it is really continuous with the chitinous integument of the neck” (p. 95). This is, we think, a mistaken view, as proved by the embryology of the Odonata and of Nematus. Our statements on this subject were first published in part in 1871, and more fully in the third Report, U. S. Ent. Commission, 1883, pp. 284, 285. We also stated that all the gular region of the head probably represents the base of the primitive second maxillæ.
[15]. After we had arrived at this conclusion, and written the above lines, we received the Zoologischer Anzeiger for March 29, 1897, in which Dr. N. Léon publishes the same view, stating that each side of the submentum is the homologue of the cardo, and each side of the mentum corresponds to the stipes of a single maxilla (p. 74).
[16]. Miall and Denny were the first to homologize the paraglossæ with the galea and lacinia, showing the complete resemblance of the second maxillæ to the first pair, remarking that “the homology of the labium with the first pair of maxillæ is in no other insects so distinct as in the Orthoptera.” We have also independently arrived at a similar conclusion, but believe that the mentum corresponds to the first maxillary cardo, and the palpifer to the first maxillary stipes, the sclerite of each maxilla being fused to form the base of the labium, i.e. the unpaired mentum and submentum.
[17]. Uzel states that what is regarded as the ligula of Campodea is formed from the sternite of the first maxillary segment; while the two parts regarded as paraglossæ grow out from the sternite of the mandibular segment, and these three structures together he regards as the hypopharynx. (Zool. Anzeiger, July 5, 1897, p. 234.)
[18]. See, also, Breithaupt, Ueber die Anatomie und die Functionen der Bienenzunge, 1886. It confirms and extends Cheshire’s work.
[19]. Cholodkowsky, Zool. Anz., ix, p. 615; x, p. 102.
[20]. Zool. Anz., ix, p. 711.
[21]. Ent. Amer., v, p. 110, Pl. II, Fig. 7.
[22]. In his account of his studies on the locomotion of insects, De Moor states that he obtained the track of each of the feet in different colors by coating them with different pigments; the insect, as it moved, left its track on a strip of paper. (Archives de Biologie, Liège, 1890.)
[23]. Carlet and also De Moor (1890) confirm Graber’s statement that in beetles the first and last appendages on the same side are in contact with the ground, while the middle one is raised. On the other side of the body the middle appendage is on the ground and the first and last one raised.