672 



DESCRIPTION OF 1VENIA CUCUMERINA. 



even in the small joints, if they be compressed between two glass 

 plates. In the ripe joint this double outlet is connected with a coiled 

 vas deferens, and with a vagina. Before 

 reaching the middle line, the latter comes 

 downwards, and becomes united with two 

 wing-like ovaries, and with a single yolk-gland. 

 The former always consist of groups of 

 branched tubules, while the yolk - gland 

 exhibits a simple lobed structure. Between 

 the two 1 lies a bladder-like receptaculum 

 seminis, and farther down, where the sheath 

 is connected with the yolk-gland, there is a 

 shell-gland, which, as usual, is composed of a 

 group of simple stalked cells. 



Occasionally one finds joints with four 

 genital openings and efferent canals. These 

 FIG. 349. Proglottides are situated in pairs opposite to each other, 



of Tcenia cucumerina in a , . , , . , ,, 



sexually mature state. ( x 20). and are separated by a wider space, so that 

 in spite of their but slight increase in size, it 



seems most natural to regard them as double joints, which, as before, 

 in the case of Tcenia saginata (p. 450), may be ascribed to a suppression 

 of the line of demarcation. On the other hand, one sometimes finds 

 only a one-sided development of the sexual organs. 2 



The first rudiments of the genital organs are observed about the 

 twentieth joint, in the form of a parenchymatous streak, which runs 

 transversely through the whole breadth of the body. The organs 

 first developed belong as usual to the male apparatus, which, in 

 addition to the cirrhus and cirrhus-pouch, consists of the much-coiled 

 vas deferens above mentioned, and of about 180 round testes, which 

 are distributed over the whole joint. 



The uterus into which the eggs are transferred from the shell- 

 gland has at the time of sexual maturity the form of a network, 

 whose cords run between the testicular vesicles, and are continued 

 laterally into a number of ceecal tubes, which in many places protrude 

 beyond the longitudinal canals. As the eggs gradually accumulate in 

 the interior of the uterus, and as their size is gradually increased by 

 the development of the embryos, both these tubes and the nodes of 



1 On this subject see Steudener's paper, " Untersuchungen tiber den feinern Bau der 

 Cestoden" (Abhandl. der naturf. Gesellsch. Halle y vol. xiii., 1877), which in many 

 particulars supplements my former communications. 



a Salzmann has noted other abnormalities of this tape-worm. The male and female 

 openings are, he says, sometimes widely separated from each other, and the male opening 

 is occasionally wanting. Embryos with a larger number of hooks, such as those observed 

 by Salzmann, have also been found by Ramsay- Wright and myself, p. 330. 



