218 SUMMARY OF CURRENT RESEARCHES RELATING TO 



first pearl, the male supplies another. The large size of the glands is 

 •correlated with this peculiar function. It may also be that the secretion 

 is not merely attractive but aphrodisiac. It is noted that in the Empid 

 Bittacus the male seizes the female while she is devouring her prey. In 

 a North American grasshopper, CEcanthus fasciatus, the female before 

 pairing licks the secretion from a special gland on the centre of the 

 metanotum of the male. In the black slug {Arion) the caudal 

 muciparous gland secretes a large globule which each slug devours with 

 avidity from off its partner. 



Study of Nepa.* — F. Brocher has made a detailed study of the 

 trachese (in larva and imago), the stigmata and siphon, the air-sacs and 

 other accessories of the? tracheal system, the respiratory movements and 

 muscles, the circulation of the air, the life-history, and the question of 

 flight. The " tracheo-parenchymatous organ " is homologous with the 

 large longitudinal dorsal muscle of the thorax ; certain sheets of tissue 

 associated with the air-sacs are homologous with other muscles in other 

 types. As in most insects expiration is mainly due to the contraction of 

 the dorso-ventral abdominal muscles ; inspiration is passive. After 

 thorough ventilation of its tracheae, the insect expires some reserve air 

 underneath the elytra. Brochet does not think that Nepa can fly at all. 



Homoeotic Regeneration of Antennae of Phasmids.f — H. 0. Schmidt- 

 Jensen, experimenting with Carausius (Dixippus) morosus, found that 

 the removal of the antennae was followed by homoeotic regeneration — 

 that is, by the growth of a part with the characters proper to another 

 member of the series. What was re-grown was a limb-like appendage, 

 e.g. with a claw-joint and three small short tarsal joints. In the 

 most pronounced cases there was a tibia-part as well. Amputations 

 across the basal joint, or between this and the second joint, produce 

 dwarfed, slightly developed homoeotic regenerations, while amputations 

 across the basal joint, or between the second and third joints, cause strong 

 well-developed homoeotic regenerations. 



Anoplura and Mallophaga from Birds and Mamnials.|— Bruce F. 

 Cummings continues his account of representatives of these orders 

 found on birds and mammals in tlie Zoological Gardens, London. He 

 establishes four new genera of Philopterid Mallophaga — Anatmcus, 

 Neophilopterus, Ibidcems, and Dollabdla, and a new genus, Struthio- 

 Upeurus, in the family Lipeuridae. 



Mouth-parts of Body-louse.§ — Launcelot Harrison gives an account 

 of the much-discussed mouth-parts of Pediculus humanus L. (usually 



* Arch. Zool. Exp6r., Iv. (1916) pp. 483-514 (20 figs.). 



t Report Smithsonian Institution for 1914 (published 1915) pp. 523-36 (2 pis.). 

 See also Vidensk. Meddels. Dansk. Naturhist. Forening, Ixv. (1913) pp. 113-34. 

 t Proc. Zool. Soc, 1916, pp. 643-93 (36 figs.). 

 § Proc. Cambridge Phil. Soc, xviii. (1916) pp. 207-26 (1 pi. and 7 figs.). 



