648 MR. F. E. BEDDABD ON 



into a thin- walled and much wider section, the muscular walls of 

 which are not more than, if so much as, half of the diameter of 

 those of the previous section. The ti'ansition is not regulai-, as 

 is figured by Meyner in the two species examined by him. The 

 diminution in thickness of the muscular layer, however, is 

 rather gi-adual at the orifice of the terminal part of the vagina 

 into the middle region. 



This middle region of the vagina contained sperm in the 

 mature segments. It apparently ends abruptly on the median 

 side, but is really connected by a very narrow tube, not wider than 

 the sperm-duct, with the distal section of the vagina, which may 

 be termed the receptaculum seminis. This .section is twice the 

 width of the last, and into it opens the duct from the ovaries &c., 

 which is about as wide as the intermediate passage connecting 

 the receptaculum and the vagina. The receptaculum seminis 

 thus begins and ends abruptly. It contains sperm, as does the 

 distal section of the vagina. At the orifice into the genital cloaca 

 the sperm-duct and the vagina lie obliquely with reference to each 

 other. The sperm-duct is anterior, but also dorsal to the vagina, 

 and a little further back is completely dorsal to it. In the veiy 

 posterior segments, which are otherwise filled with the distended 

 uterus, the vagina with its receptaculum seminis shows an alter- 

 ation. It has increased in size, owing to its being gorged with 

 sperm. 



I presume, at any rate, that the granular, in places fibrous- 

 looking, contents of the vagina are sperm, though they have a 

 different appearance from, and stain differently to, the obvious 

 spermatozoa which fill the neighboiu'ing vesicula seminalis. In 

 the posterior proglottides the vagina shows no diflerentiation into 

 regions such as have just been described, excepting the proximal 

 muscular region near to the external pore. The rest forms a wide 

 uniform tube, and in longitudinal horizontal sections is seen to be 

 as wide as the proglottid is long or nearly so. In exceptional 

 cases even this amount of differentiation in the vagina is lost and 

 the wide tvxbe pushes itself as far as the external pore, crushing 

 the cirrus sac into a mere rudiment. 



From the above detailed description of this Tapeworm there 

 may be absti'acted the following resume of its characters : — 



Length of about 150 mm., greatest breadth 10 mm,. Shape an 

 elongated cone, gradually diminishing to scolex. No neck, the 

 strobilisation commencing i'mmediatelij after scolex. Proglottides very 

 short and toide, not increasing posteriorly in length. Scolex with 

 four suckers looking ujnvards, completely retractile into head, with 

 black piigment. No armed rostellum. Dorsal and ventral excretory 

 tubes at first subequal, later the ventral very much the larger ; the 

 two tubes are superjyosed dorso-ventrally, ivith a transverse trunk 

 connecting the ttoo ventrals. Genital pores alternate, frequently 

 ivith regidarity. Generative ducts dorsal to toater -vessels and nerve. 

 Testes numerous, forming a layer two or three thick, reaching com- 

 pletely betiveen ivater-vessels, anterior and dorsal in position. 

 Cirrus feeble, no sperm-sac (vesicula seminalis). Sperm-ducts 



