86 Annals of the South African JS'hiscum. 



means of four separate pores, which are situated each at the apex of 

 a, large papilla. 



These papillee are arranged in two pairs. Those of the anterior 

 pair are placed on each side of the genital papillae close to the 

 bases of the genital legs, while the posterior pair lie nearer together 

 but at some distance behind the anterior pair. The exact position 

 of these papillae is accurately shown in fig. 11, ac.g"^, ac.g^. They 

 are all about the same size and are furnished with the usual minutely 

 echinate scales on their surfaces. They are conspicuous in the living 

 animal, especially the posterior pair, having the appearance of 

 rounded pallid tubercles with an opening at the tip of each. 



Bach of the posterior glands consists of a duct (r.ac.g'^) nearly 

 equalling the hinder portions of the paired vasa in thickness in the 

 dissected specimen (fig. 15) and leading from the external pore to a 

 large, elongate, collapsible, carrot- shaped vesicle {r.v), w^hich con- 

 siderably exceeds the ductus ejaculatorius in diameter. This vesicle 

 tapers root-like at its posterior end, where it passes over into the 

 efferent duct, but at the anterior end it is abruptly constricted and 

 <3ontinued into a very fine short duct, which enters another elongate 

 enlarged tube (r.c). At the end of the latter is a tubular appendage 

 (ap), ending blindly and terminating the gland.''' 



In sections the efferent duct of the posterior glands may be easily 

 recognised and distinguished from the numerous other tubes of this 

 region of the body by the curiously jagged and irregular outline 

 of its lumen, into which processes or ledges containing the nuclei 

 project (figs. 30 and 31). A distinct muscular sheath is present. 



Both large vesicles are shown in section in fig. 25, r.v being cut 

 through the thickest part of the right vesicle and l.v through the 

 thinner posterior part of the left one. The walls form a simple 

 epithelium of cubical or even somewhat flattened cells with much 

 larger nuclei than those of the duct. In each vesicle is a small 

 ■quantity of coagulated secretion. It is evident that these vesicles 

 are capable of great distension, as those in the dissected specimen 

 (fig. 15) are about three times the actual thickness of those in the 

 sections (fig. 25). The usual muscular coat is present but is ex- 

 tremely thin. 



In the middle region of the gland the cells suddenly become 

 elongated and the epithelium is therefore very thick (fig. 25, 

 r.c and l.c). 



* In the specimen dissected the two cai'rot-shapcd vesicles lay on the left side 

 of the body with their obtuse ends in front, while the middle and terminal sec- 

 tions of the glands varied in arrangement in the manner shown in fig. 15. 



