T^NIA SAGINATA GOEZE 75 



pairs of which are lateral, one pair dorsal and one pair ventral. 

 The dorsal and ventral nerves lie outside the transverse muscles. 

 Of the three lateral nerves of each side the middle one is by far 

 the largest. The longitudinal nerves give off minute branches 

 to the sense cells found in the parenchyma. In the scolex the 

 longitudinal nerves are connected with each other by com- 

 missures with ganglionic enlargements forming the central 

 nervous system. 



The excretory system consists typically of two pairs of longi- 

 tudinal canals opening to the outside on the last proglottid. Of 

 these the inner pair is considerably less developed than the outer 

 pair and seems to be missing in older proglottids. Close to the 

 posterior edge of each proglottis is a transverse canal connecting 

 the two longitudinal canals. The collecting tubules which are 

 numerous are very thin tubes opening into the longitudinal 

 canals. The distal end of the tubules is closed by a flame 

 cell. 



Reproductive system. Taenia saginata is a hermaphrodite 

 and each proglottid has a complete set of reproductive organs. 

 The genital papilla or the wall of the genital atrium is situated 

 either on the left or on the right side of the proglottis. The male 

 reproductive organs consist of several hundreds of small round 

 testes situated to the inside of the dorsal transverse muscles ex- 

 tending over almost the entire proglottis. The vasa e/erentia 

 open near the middle of the proglottis into the vas deferens, a 

 canal which appears under low power as a straight line running 

 to the genital atrium, but which in reality is convoluted through- 

 out its entire length. The end portion of the vas deferens, which 

 is inclosed in a muscular cirrus pouch, may be protruded as a 

 cirrus through the male genital opening into the atrium. 



The female reproductive organs are much more complicated. 

 The female genital opening situated in the atrium under the male 

 genital opening, leads into a thin, straight tube running parallel 

 with the vas deferens. This tube is the vagina. Towards the 

 middle of the proglottis the vagina bends downward and forms 



