156 



INVERTEBRATE MORPHOLOGY. 



end of the proglottid. The oviduct soon after leaving 

 the ovary unites with the yolk-duct (vid) coming from the 

 albuminous vitellarium (vi), which consists of a number of 

 glands scattered through the parenchyma similarly to the 

 testes. At the point of union with the yolk-duct the oviduct 



vld 



va 



ov 



FIG. 82. PROGLOTTID OF Tcenia filicollis (after KRAEMER). 



c = cirrus. te = testis. 



n = nerve. ut = uterus. 



ne = excretory canal. va = vagiua. 



ov = ovary. vd vas deferens. 



sg = shell-gland. m = yolk-gland. 



md = yolk-duct. 



enlarges, receiving at the enlargement the secretion of a num- 

 ber of unicellular glands composing the shell-gland (sg). 

 From this enlargement two tubes arise : one, the vagina (va), 

 runs almost directly forward to open into a chamber, the 

 genital atrium, which contains also the cirrus-sac and com- 

 municates directly with the exterior; while the other, the 

 uterus (ut), after a somewhat convoluted course opens iude- 



