T. B. ROSSETER ON THE GENITAL ORGANS OF TAENIA SINUOSA. 89 



•ventrally under the distal end of the vesicula seminalis and joins 

 the receptaculum. seminis. 



The receptaculum seminis (Fig. 1, j) is a triangular sac with 

 rounded corners at its base. The vaginal canal enters it at its 

 apex. It has a length of "227 mm., and its base is "097 mm., its 

 basal angle being thus more contracted than the lateral angles. 

 It is situated in the anterior distal portion of the proglottis, 

 ventral to and immediately under the moniliform testis, and 

 under such circumstances it is somewhat difficult to discriminate 

 between them. Its efferent canal leaves it on the ventral side, 

 runs backwards, then sharply curves round and passes on to join 

 the ovarian ducts. 



The ovaries (Fig. 1, V-l") are two orbicular lobed glands, situated 

 proximally and distally in the ventral posterior portion of the 

 segment, and have a mean diameter individually of '211 mm. 

 Their ducts coalesce with the duct of the receptaculum seminis, 

 and thus form the fructifying canal, which descends into the 

 yelk gland. 



The yelk gland (Fig. 1, m) is situated anterior to, and the shell 

 gland (Fig. 1, ri) posterior to, the ovaries, in the median line of the 

 proglottis. The former is globular, and the latter, being pyriform, 

 runs distally, and is partially obscured by the posterior portion 

 of the distal ovary. 



I have not had the opportunity to study the uterus with its 

 uterine ova, in consequence, as so often happens in experimentally 

 bred platyhelminths, of the segments not having arrived at the 

 •uterine stage of development. 



Explanation of Plate 5. 



Fig. 1. Male and female genital organs in situ, x 155 : a, 

 testis ; b, vas-deferens ; c, vesicula seminalis ; d, 

 male genital pore ; e', cirrus extruded ; e', cirrus- 

 pouch ; f, spiculiferous globule ; g'-g', prostate glands 

 with their ducts ; h, female genital pore with vagina ; 

 i, vaginal canal (Krabbe's thin undulating streak) ; 

 j, receptaculum seminis ; k, efferent duct of recepta- 

 culum seminis or fructifying canal, making a junction 



