694 



THE ANATOMY OF BOTHEIOCEPHALUS LATUS. 



We have already seen the importaBce of this discovery of the vagina 

 and its aperture for the right understanding. both of the morphology 

 and physiology of the reproductive organs of Bofhriocephalus. 



Since the vaginal aperture, as above noted, 

 lies at the bottom of the anterior genital 

 opening, which also includes the opening of 

 the cirrhus-pouch, and was till Stieda's dis- 

 covery described as simply the male aperture, 

 there is a certain justification for speaking of 

 a sexual cloaca in Bothriocephahis. It must, 

 however, be kept in mind that this cloaca is 

 in nowise to be associated with the structure 

 of the same name in the Tcenice. While the 

 latter, in virtue of its depth and narrow 

 aperture, appears as a morphologically inde- 

 pendent structure, which does not alter its 

 form or character even when the penis is 

 protruded, the cloaca-like cavity in the form 

 under discussion is different, inasmuch as, on 

 protrusion of the penis, it is more or less com- 

 pletely smoothed out by the retraction of the 

 lips ; and that so far that the vaginal aperture 

 comes to lie exposed on the surface of the 

 joint, below that of the cirrhus, in a situa- 

 tion which in other species is the persistent 

 Fm. 363.— Longitudinal one, e.g., in B. maculatus of the leopard and 



diagrammatic representation , . , , , . , , . i ■■ 



of tbe three generative ducts ^lon, Where there IS aimost no gemtal cloaca, 

 in their connection with the ^his being SO, it is perhaps more correct to 



the genital apertures and 

 with one another, w.d., vas 

 deferens ; c.p., cirrhus-pouch; 

 v., vagina ; «., uterus. 



regard the genital pore of this worm as the 

 result of simple invagination, as Eschricht 

 had indeed done in designating the lip-like 

 marginal swelling the " preeputium." 



The Cirrhus, when protruded, is seen as a slender cone (Fig. 362), 

 not unfrequently protruding half a millimetre, or even more, out' of 

 the genital aperture. It has accordingly a much more considerable 

 size than in the cystic tape-worms, in which {T. saginata) it is hardly 

 ever larger than 0'18 mm. At its base it measures in the present 

 species fully 01 mm., which is more than double its measurement at the 

 end. The canal which penetrates it, and opens at its apex, collapses 

 in the empty state, but is not unfrequently filled with spermatozoa, 

 and then occasionally measures as much as 0'02 mm. or more. 



In spite of its considerable size, the cirrhus of Bothriocephcdus is 

 nothing more than^^^g^]^]^-(§.^g^^ed anterior portion of the 



