112 



THE CESTOIDEA 



Fio. X. 



Bothriocephalus latus, L. The genital organs (after Sommcr and Landois). The upper figure 

 shows the female organs seen from below ; the lower figure, the male organs from above. In 

 each case only the central part of the proglottid is represented, so that only a small part of 

 the testes and vitellaria is shown (see Fig. III. 4) ; the anterior and posterior boundaries, 

 however, are shown, a, the prominent "cirrus sac"; b, the cirrus, partly everted, carrying 

 the aperture of the sperm duct at its end ; c, the genital atrium and pore ; <i, the vaginal pore 

 opening into the atrium ; e, the large coiling uterus ; /, the uterine pore ; g, the vagina in the 

 middle line ; h, germarium ; t, shell gland ; j, vitello duct ; k, lateral nerve ; I, vitellarium ; n, 

 cirrus canal traversing the muscular tissue of the cirrus sac in order to reach the male pore 

 (see upper figure); p, sperm duct; q, seminal vesicle; r and x, vasa efferentia ; s, lateral ex- 

 cretory canal ; t, testicular follicles. 



