478 MICHAEL F. GUYER, 



of them in the froutal sections. Occasioually, certaiu modificatioDS 

 are met witli iu which tlic rouud bulbs sliow a tendeucy to merge 

 intü one aiiother aud form a long vesicle. 



C i r r u s and c i r r u s p o u c h. The cirrus (Figs. 6 and 7 c) is 

 siniply the modified end of the Vas defereus which, after it reaches the 

 cirrus pouch, becomes much straighter, of less diameter (29 ii) and 

 shows but very few coils. The tip is usually slightly enlarged al- 

 though occasionally it is conical. It often lies thrust slightly out of 

 the sac and except for the smaller diameter seems to be but little 

 modified from the Vas deferens. A trimming or border of fine 

 chitinous poiuts, similar to those already described for T. saginata 

 by Leuckart (1886, p. 440) cannot be defiuitely made out. In one 

 or two cases very delicate markings were discernable, but whethcr 

 they were points or simply wrinkles could not be determined. The 

 represeutation in the drawiug (Fig. 7 c) is somewhat exaggerated. 

 The cirrus is so arranged that in extention the serainal duct is evagiu- 

 ated or turned inside out for a short distance, forming the copu- 

 latory organ. To be more explicit, the outer end of the cirrus 

 pouch is reflected back, forming a pit which is continuous with the 

 seminal duct. 



When the muscular wall of the sac coutracts a regulär prolapsus 

 of the duct results and its inner side is forced out to the exterior. 

 This process is well illustrated by beginning at the base of a gloved 

 finger and gradually turning it inside out ; although of course iu the 

 case of the worm the pressure is distributed over what corresponds 

 to the entire outer surface of the glove finger, thus forcing the tubc 

 to double back upon itself and turn inside out. This arrangement is 

 also found in T. saginata. 



The cirrus pouch (Fig. 7 c.p) is somewhat pear-shaped and 

 measures 0.31 mm in length. Its walls are made up largely of mus- 

 cular, web-like strukture in which the fibres run diagonally. On the 

 inside are retractor muscie fibres (Fig. 7 r.mx) which attach the 

 cirrus to the wall, and also, many connective tissues fibres. Numerous 

 deeply staining bodies, which for want of a better name are called 

 free nuclei^'^ (Fig. 7 f.n) are present and are distributed throughout 

 the inner network of fibres. In addition to the nuclei, numerous 

 other minute bodies which resemble them very closely are present. 

 Upon close examination the latter are seen to be the cut ends of 

 sniall muscie fibres. These small bodies (both nuclei and small 

 umscles fibres) are found also along the edge of the pore plug and 



