CESTODA. 



257 



longer. The head is club-shaped, and is provided with two slit-like pits. The 

 cortical parts of the lateral regions of the body contain a number of round 

 masses of granules, the yolk-glands (Fig. 216, Dst), the contents of which are 

 poured into the shell glands (coiled glands) through the so-called yellow ducts. 



The genital openings lie close together, one behind the other, in the midst of 

 the segment (Fig. 216, a). The anterior and larger belongs to the mal/generative 

 apparatus, and leads into the muscular terminal portion of the vas deferens, 

 which is enclosed in the cirrus sheath (Fig. 216, Ob), and can be evaginated 

 as the cirrus. The vas deferens just before its entrance into the cirrus pouch 



D.st, 



FIG. 212.Caryoi)hyllaeus muta- 

 Ulis (after V. Carus). W ex- 

 cretory canal ; H testes ; Vd 

 vas deferens ; Vs vesicula 

 seminalis ; P penis ; Ov ovary ; 

 D yolk - gland ; Dg duct of 

 yolk gland ; Ut uterus ; Rs 

 receptaculum seminis. 



~JC.se 



FIG. 213. AmpMlina foliacea, showing 

 the generative ducts. S.g sucker; Ut.m 

 opening of uterus; D.st yolk-gland; 

 K.st ovary"; Vg opening of vagina ; C 

 opening of vas deferens (after Wagener). 



is dilated (Fig. 216, b) to form a large muscular swelling (the vesicula seminalis?). 

 It then becomes coiled, and passes in the direction of the long axis of the 

 segment on the dorsal surface and divides into two side branches. These 

 receive the efferent canals of the delicate testicular sacs, which occupy the 

 lateral parts of the middle layer (T). The female genital opening (Fig. 216) 

 leads into a vagina ( Va] situated behind the pouch of the cirrus, and frequently 

 filled with semen. This vagina runs as a tolerably straight median canal on the 

 ventral surface, and opens by a short, narrow tube into the oviduct. The 

 vagina also functions as a receptaculum seminis. There is yet a third opening 



s 



