86(5 UR. F. E. BKDDARD ON 



§ Genital Ducts. 



This worm is characterized by the great depth of the genital 

 atrium, which is much more developed than in most tapeworms 

 and quite as much so as in any. The orifices of these follow in 

 successive proglottids upon the same side of the body. In the 

 ripe proglottids they are situated quite posteriorly and, therefore, 

 the genital ducts which open into them run forwards towards the 

 anterior I'egion of the proglottid. The genital atrium, or genital 



Text-fig. 144. 



sp.d. 





X 



V 



\ 



Part of a horizontal section through a proglottid of Riigonodirum oedicnemi, 

 showing a generative aperture. 



c. Cirrus extruded from cirrus-sac (shown \yiag in front of it) and received within 

 vagina («;)• ('■ff- Verj' deep cloaca genitalis, sp.d. A coil of sperm-duct. 



cloaca, is lined by a prolongation of the outer cuticle ; outside of 

 this is a very thick layer of rather stout muscle-fibres which, 

 when the genital cloaca is cut through transverselj^ to its axis, 

 are seen to have a radial arrangement. The cavity is circular in 

 transverse and oblong (more or less) in longitudinal section. At 

 the base, where the genital ducts join it, it widens out and forms 



