T. B. ROSSETER ON THE GENITAL ORGANS OF TAENIA SINUOSA. S3 



prepared and mounted specimens. Dujardin gives the length 

 of this tape-worm as from 50 mm. to 160 mm. The Zeder- 

 Rudolphi specimen -was 330 mm. My longest specimen produced 

 by infection was 18 mm. Thus it will he seen that it has 

 no pretensions to the length of the Zeder-Rudolphi or even 

 the Dujardin specimen; but it is a perfect worm, minus the 

 uterine sac with the uterine eggs. 



Male Organs. 



The male genital pore (Fig. 1, d) — I use it in the 

 singular — is unilateral, and is situated on the anterior lateral 

 border of the segment. It is cup-shaped ; its orifice has a 

 diameter of '026 mm., and the diaphanous cup has a depth 

 of about '065 mm., and is easily overlooked. The male organs are 

 situated well up in the anterior portion of the segment, being 

 overlapped somewhat considerably by the posterior transverse 

 border of the preceding segment. They consist of a cirrus, with 

 its sheath, a vesicula seminalis, a vas-deferens, a monoecious testis, 

 and paired prostate glands. In a mature specimen the proglottis is 

 325 mm. long, and in width 1 "747 mm. anteriorly, and 1*976 mm. 

 posteriorly. 



The testis (Fig. 1, a) is a subglobular organ, having an 

 approximate diameter of *162 mm. In those young segments 

 which are approaching maturity it appears to be situated 

 in the centre, or nearly so, of the anterior portion of the pro- 

 glottis ; but as the segment develops, and with it the generative 

 organs, the testis gradually moves backwards towards the anterior 

 distal lateral border, on its dorsal side immediately over the distal 

 end of the receptaculum seminis. The growth of the spermatozoa 

 within the spermatic sac is analogous to — in fact, is a counterpart 

 of — the development of the spermatozoa of T. coronula, with this 

 exception, that the bundles of spermatozoa do not form coils or 

 strands, but are passed on individually through the vasa-efrerentia 

 to the vesicula seminalis. The head of the spermatozoon is a 

 spatulate cell containing a cellule or nucleus of plastic substance 

 easily stained by either haemalum or haematoxylin, whilst the 



