54 ENTOZOA UF MOXOTIJKMAIA, ETC., ii., 



The testes occupy two fields, an anterior and a posterior, 

 separated by the female glands. The anterior field con- 



sists of from fourteen to seventeen vesicles lying between the 

 cirrus-sac, vas deferens, female glands, and the dorsal vessel 

 The posterior field consists of about the same number of 

 glands, these occupying the whole of the dorsal portion of 

 the medulla lying between the female glands and the trans- 

 verse excretory vessel, and between the longitudinal excretory 

 vessels in the transverse plane. There are thus about thirty- 

 two vesicles altogether. They are rounded or slightly ellip- 

 tical, having a diameter of from 0-038 to 005 mm. ; and are 

 disposed in two rows in the dorsal region of the medulla. 

 Lying in the angle formed by the vagina and the cirrus-sac, 

 is the vas deferens, a closely coiled structure. From it there 

 passes, forwards and inwards, an uncoiled portion which 

 enters the cirrus-sac in the extreme anterior part of the 

 proglottis. 



The cirrus-sac is a very long tubular organ, lying in the 

 anterior corner of the segment, and extending from near the 

 middle of the anterior margin to the genital cloaca. It fre- 

 quently exhibits a few loose open coils, thus resembling part 

 of a cork-screw. Its total length is about 0-16 mm., and the 

 breadth 0034 mm. The musculature is well developed. From 

 its inner end, retractor fibres pass off laterally and slightly 

 ventrally. Within the sac, one may see the coiled male duct 

 ending at the male pore. No distinct external vesicula semi- 

 nalis was seen. In most of the segments the cirrus was 

 partly everted, and lying in the genital cloaca. The total 

 length of the eversible portion exceeds 0-10 mm. The organ 

 is rather wider at its base than at its extremity. Its surface 

 appears to be devoid of armature. In no case was the cirrus 

 seen projecting much beyond the genital pore, but as the 

 cirrus-sac still possessed its corkscrew-like form, it is quite 

 likely that the fully everted organ may project some little 

 distance through the j^ore. In one of the segments, self- 

 fertilisation was observed (Fig. 10), the cirrus being bent 



