T. B. ROSSETER OX DREPANIDOT^NIA VENUSTA. 17 



furnished, clasp and retain the ciiTus until the vesicula seminalis 

 is emptied of its contents. 



The vaginal canal runs downwards somewhat obliquely, then 

 ascending it curves round and overlaps the cirrus pouch, and again 

 descends to form a junction with the receptaculum seminis. The 

 latter part of the canal is annulated, commencing where the 

 canal overlaps the cirrus pouch, so that it can scarcely be 

 considered a continuation of the vagina, but must be regarded as 

 a ductus efferens. The duct is circular (Fig. 10, </), and in cross 

 section its diameter is 0'013 mm. 



The receptaculum seminis (Fig. 10, h) is a large pyriform sac, 

 being 0"236 mm. long and 0*160 mm. wide, I consider it to 

 be a swollen continuation of the ductus eflferens of the vagina. 

 Its situation in the proglottis never varies j it occupies the 

 anterior median line of the segments close up to where they are 

 connected, and is always overlapped by the posterior dorsal margin 

 of the preceding segment. It is filled with spermatozoa before 

 any sign of the uterus is visible in the segment, and is almost 

 invariably the last organ to become absorbed in the uterine or 

 ripe proglottis. 



The ovary is a paired organ (Fig. 10, I, m). Its "Anlage" 

 commences in the median line on the ventral side of the segment. 

 As it progresses it gradually pushes its way backwards to the 

 distal third of the segment ; thus it lies laterally in the segment. 

 It is not a fan-like structure, as in the Mammalian tsenije, but 

 consists of two lobes, each lobe being composed of a number of 

 glands whose efferent ducts empty themselves into one common 

 ovarian canal. The efferent ducts from each ovary (Fig. 10, J, ^•), 

 previous to their forming a common duct, are inordinately long, 

 the aporose duct being from its position the longest. Each lobe 

 is encapsuled by 'a thin membrane. One lobe lies on the porose 

 and the other on the aporose side of the proglottis. The former is 

 composed of five glands, and is 0*270 mm. long and 0*101 mm. 

 wide. It presses close up to the anterior margin of the segment. 

 The aporose lobe contains six glands ; it is 0*304 mm. long, and 

 0*135 mm. wide. 



Immediately anterior to, and in the median line of the ovaries 

 in the centre of the proglottis, is a comparatively small heart- 

 shaped or triangular organ, the yelk-gland (Fig. 10, n). Its 

 length from apex to base is 0*027 mm., width at base 0*017 mm. 

 JouRN. Q. M. C, Series II., No. 42. 2 



