THE GENERATIVE ORGANS. 589 



The Sexual Organs of Tcenia echinococcus exhibit many striking 

 peculiarities, which, when compared with those of other tape-worms, 

 contribute not a little to justify the independent position which we 

 have claimed for it here. 



The Male Organs strike one by the unusual size of the cirrhus- 

 pouch, which measures almost 0'5 mm., and, by its club-shaped, 

 thickened posterior end, reaches to the middle line of the newly 

 fertilised joints. The cirrhus itself has apparently a greater indepen- 

 dence than is the case in the other cystic tape-worms. It lies in the 

 anterior portion of the cirrhus-pouch, like the glans in the prseputium, 

 and is not unfrequently protruded. Sometimes it is found in the act 

 of copulation. The sexual cloaca is destitute of a proper papilla, 

 the penis itself is bent into a sort of hook-shape, and is sunk into the 

 anterior end of the adjacent vagina. 



Before its entrance into the posterior end of the cirrhus-pouch, the 

 vas deferens makes several irregular coils, which are mostly distended 

 with spermatozoa. In the testes, too, the spermatozoa are readily 

 recognisable since they possess an unusual length and thickness. 

 They are usually seen rolled up in curls, and can sometimes be observed 

 passing into the thin efferent canals of the testes. The size of the 

 testes is quite appreciable, averaging about 0*07 mm., and their number 

 is proportionately reduced to about sixty. 



The Female Organs. The vagina is characterised by a longitudinal 

 enlargement (with a transverse diameter of 0'05 mm.) in the middle 

 of its course. In this there can be seen a yellow chitinous lamella, 

 with numerous points directed outwards. It is the same struc- 

 ture which we noted in the other cystic tape-worms. Its posterior 

 end leads to a distinct bladder (0*014 mm.), whose contents con- 



vaacular system of Cestodes, and furnish also an almost exhaustive examination of the 

 latter system. The two memoirs are (1.) by Fraipont, " Rech. sur 1'appareil excreteur des 

 Trematodes et Cestoides," Archives de EioL, t. i., p. 415 ; and (2.) by Pintner, " Unter- 

 suchungen iiber den Bau des Bandwurmkorpers," Arb. des Zool. Instituts zu Wien, Bd. 

 iii., 1880. According to the harmonious results of both, the cilia are never found in the 

 course of the finer vessels, but only at their ends, and that in a sort of funnel-like enlarge- 

 ment, as was already known in part in regard to the Trematodes, having been demonstrated 

 by me in 1863 on the embryos of Distomum hepaticum (first German edition of this work, 

 Bd. i., p. 766). The funnels contain each only a single cilium, and this belongs to a cell 

 which shuts the mouth of the funnel like a lid, and was regarded by Pintner as a gland- 

 cell. The fine vessels pass out from the funnels, open without marked enlargement either 

 alone or in groups, and often after ramification, into the longitudinal vessels. The latter 

 never ramify, but are clad externally with an epithelium-like cellular coating, which has 

 probably a secretory character. Besides the existence of the ciliary apparatus, that of the 

 nervous system has been established by Pintner. The researches of this young investi- 

 gator refer primarily and principally to the Tetrarhynchi, which have less interest for us 

 here, although alluded to above (see p. 295) ; but there are many references to the 

 Taeniadae. The reports on the finer anatomy of the tape-worms are in beautiful harmony 

 with my results, though there are divergences here and there. 



