T^NIA. 



145 



Y'lg. 78.— T^.NiA Saginata. 



(i\.fier Leuckart.) 



There is a very thin cuticle and a rather indefinite layer 

 of ectoderm which merges into the parenchyma. In this tissue 

 are small calcareous bodies. 

 The muscles are arranged in a 

 transverse series and a scat- 

 tered longitudinal series out- 

 side it. 



In the parenchyma are 

 found the complex repro- 

 ductive organs. Tcenia^ like 

 Disto77iuni^ is hermaphrodite, 



... and the sexual 

 Reproductive. 



organs are re- 

 peated in each proglottis. 

 They mature gradually, hence 

 the front proglottides show 

 an earlier stage than the 

 hind ones. Those front pro- 

 glottides which show sexual 

 organs have male organs only. 

 The middle ones show both 

 sets of organs and the " ripe " 

 hind ones show a portion of 

 the female organs only. The 

 common sexual opening is 

 found on the right side in 

 one proglottis, on the left in 

 another. The testis is a 

 branched organ opening by a 

 vas deferens to a pejiis. The 

 paired ovaries lead by ovarian 

 ducts into a median oviduct. 

 This oviduct first receives the 

 opening of the sperm -duct 

 and then passes through the 

 shell-gland to the uterus. In 

 the shell-gland it receives the 

 vitelline duct from the yolk- 

 gland. The sperm-duct opens 

 at its other end into a seininal 



receptacle, a chamber in which selected portions from a single specimen. 

 M. II 



