602 DR. F. E. BEDDARD ON 



short distance in front of its opening into the cirrus sac. The 

 course of the sperm- duct is roughly parallel to that of the vagina, 

 with which it might be sometimes confused in those cases where 

 the vagina has not so abrupt a transition into the receptaculum. 



Along the course of the sperm-duct, which in ripe segments is 

 gorged with sperm almost throughout, there lie masses of what 

 appear to be prostatic cells, similar in the fact of their existence 

 to those of Inerinicapsifer, but different in appearance. In the 

 present species these cells are of a clear, almost hyaline, ap- 

 pearance, which is possibly due to the state of their activity at 

 the time when the worm was killed. In Inermicapsifer capensis 

 and in the species which I originally named Thysanotmnia gam- 

 hiana, the prostatic cells were darkly staining and granular. 

 Nevertheless, they appear to be equivalent structures in the two 

 tapewoi'ms. In sections where the sperm-duct appears in trans- 

 verse section, these cells present the appearance of a winding duct 

 cut transversely. This appearance is due to the clear cells 

 clustered round the actual sperm-duct, which, as already said, is 

 narrow of calibre close to where it opens into the cirrus sac, and 

 thus not obvious in such sections. There can be no mistake, 

 however, in transverse sections of proglottids, where the course 

 of the sperm-duct is easily to be followed owing to its being filled 

 with sperm. 



In the second and larger individual there are certain definite 

 differences in the form of the sperm-duct. The tube has no such 

 great dilatation into a vesicula seminalis, and it is very much more 

 coiled as it approaches the cirrus sac. It has, in fact, the large 

 and close coil which is so typical of tapeworms. There is certainly 

 nothing of the kind in the other individual. The clear cells 

 already spoken of form a complete layer one cell thick round 

 the mass of sperm in the sperm-duct, and are therefore, I take it, 

 simply the epithelial wall of the sperm-duct. As the sperm-duct 

 was in parts full of sperm, this difference cannot be owing, I 

 believe, to the different stages of the maturity of the proglottids 

 in this tapeworm as compared with those already described. It 

 must, I think, be a specific difference, with which also, it will be 

 observed, go differences in the position of the ovary and vitelline 

 gland. 



The cirrus sac of this worm is not at all large as in the allied 

 forms comprised in the genera Inermicapsifer and ZschoTckeella. 

 It can be seen in sagittal sections to lie straight in front of the 

 vagina close to the external aperture, and I have not noticed any 

 genital cloaca. There is certainly nothing of any size, and in one 

 section the penis was seen to protrude on to the exterior directly 

 from the cirrus sac without any intermediate and common 

 chamber. The cirrus sac is oval in form and surrounded, as is 

 usual, by a strong layer of muscles. I could not see any indications 

 of a flask shape such as is so common in tapeworms. In the in- 

 terior of the sac are the usual nuclei belonging, it is to be presumed, 



