TANTA. 145 
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. Zenza, like 
Distomum, is hermaphrodite, 
and ‘the sexual 
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 ¢estis is a 
branched organ opening by a 
vas deferens to a penis. The 
paired ovaries lead by ovarian 
ducts into a median ovéduct. 
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 seminal 
receptacle, a chamber in which Selected portions from a single specimen, 
M. II 
Fig. 78.—Tania SAGINATA. 
(After Leuckart.) 
Reproductive. 
