30-1 T. B. ROSSETER ON HYMENOLEPIS FARCIMINALIS. 



condition ; the crateriform aperture still exists, and is not 

 obliterated in the uterine segments. 



The male organs are dorsal and the female ventral in the 



segment. 



There are three testes, one proximal and two distal (Fig. 2, t, t, t). 

 These are all semi-oval, almost pyriform. The proximal has a 

 diameter at its basal or widest portion of 0*102 mm., whilst the 

 distal testes are a trifle larger, being 0*106 mm. in diameter. One 

 is slight] v anterior to the other. The efferent duct (Fig. 2, d. e.) 

 of the extreme distal testis makes a junction with the duct of 

 the other, whilst the efferent duct of the proximal runs distally, 

 curves slightly, makes a junction with and pours its semen into 

 the vas-deferens. The vas-deferens (Fig. 2, v.d.) swells at in- 

 tervals into small vesicles (Fig. 2, vsc.) ; these collapse, and 

 cause the onward progress of the sperm into the vesicula 

 seminalis (Fig. 2, v.s.). This is a long attenuated sac with a 

 filiform sinuous ductus efferentia which a little farther on swells 

 out into an " expulsion -blase" lying within an ampulla-formed 

 cavity, a continuation of the genital aperture (Figs. 2 and 17). 

 The distal portion of the " blase " is a large swollen sac which is 

 invariably filled with spermatozoa ; then follows a slight con- 

 striction, then another bulb (the middle vesicle), again a con- 

 striction, and then another swelling, which is seen to be the 

 cirrus-pouch containing the cirrus with its sheath. The middle 

 portion is studded anteriorly with small glandular bodies which 

 I take to be prostate glands. They are unequal in size, the 

 largest having a diameter of 0-025 mm. The " expulsion -blase" 

 is composed of longitudinal and circular muscular fibres, whilst 

 retractor muscles radiate from it to the walls of the ampulla- 

 sac (Fig. 11. amp.). 



The cirrus (Fig. 2, c.) is a comparatively short, smooth, hollow 

 rod 0*0G8 mm. in length, with a diameter of 0*007 mm. Diameter 

 of sheath 0*02 mm., length of pouch 0"18 mm., diameter of pouch 

 0*031 mm. The cirrus is never, judging from my specimens, 

 extruded to any great length, and the sheath is extruded with it 

 previous to copulation. In fact, I have formed the opinion that in 

 coition the sheath performs the function of a sucker to the vulva. 



