NO. 2 RECOGNITION AMONG INSECTS — McINDOO 63 



(c) ANAL GLANDS OF ANTS 



Forel (1878) was able to find anal glands in only the workers and 

 queens belonging- to the subfamily Dolichoderidae (a division of 

 Formicidae). He has found them in Bothriomyrmex meridionalis, 

 Tapinoma erraticum, T. nigerrimum, Liometopum (?) sericeum, 

 DoUchoderus (Hypoclinea) attelahoides, and D. bispinosus. The 

 gland in each of these species is very similar to that of Bothriomyrmex 

 which he describes in detail. Just above the anus lies a slit-shaped 

 external opening which leads into the efiferent canal of the paired 

 gland. Both reservoirs, which occupy about half of the space at 

 the posterior end of the abdominal cavity, run into the same efferent 

 canal. At the outer side of each reservoir lie the unicellular glands, 

 arranged grapelike. A large collecting tube runs from the bunch of 

 cells and empties funnel-like into the base of the reservoir. Each 

 spherical cell has a large nucleus containing many nucleoli. Wound 

 around inside the cell he saw a chitinous secreting tubule surrounded 

 by a transparent sheath ; the tubule runs into the collecting tube. A 

 protoplasmic sheath containing nuclei encloses the secreting tubule 

 outside of the cell, and even the collecting tube is likewise enclosed. 

 Tracheal branches run between the gland cells and seem to be 

 closely connected with the secreting tubules. The reservoirs are well 

 supplied with muscles and also with tracheal branches. Forel claims 

 that most ants have a more or less strong and characteristic odor; 

 the two species, Lasiiis emarginatus and L. fuliginosus, have differ- 

 ent odors ; in these the scent-producing organ lies in the mandibles 

 (Oberkiefer) and metathorax. 



II. INVAGINATED SACS AND POUCHES AT THE DORSO-POSTERIOR END 

 OF ABDOMEN AS SCENT-PRODUCING ORGANS 



(a) INVAGINATED SACS AND POUCHES OF CERTAIN ORTHOPTERA 



Vossler (1890) describes this organ in the ear-wig, ForRciila 

 auricularis, as two pairs of lateral structures in the third and fourth 

 abdominal terga. Each one of these consists of a reservoir having a 

 narrow neck which opens to the exterior through a slit. Muscles are 

 attached to the neck of the reservoir to open and close the slit. The 

 walls of the reservoir are composed of unicellular glands, each of 

 which besides having a nucleus has also a vacuolated area from which 

 runs a secreting tubule into the reservoir. In the reservoir he found 

 a yellowish or brownish liquid, which may be thrown from 5 to 10 

 centimeters from the insect. 



