593 
and from this numerous strands extending to the periphery of the cell, 
where a more or less continuous layer of cytoplasm exists. Between 
the strands of cytoplasm large spaces, doubtless filled with fluid in 
the living cell, appear. 
The testes arise in the inner parenchymal region, i. e., the region 
enclosed by the muscle layers and penetrated by the scattered dorso- 
ventral muscles. The region of testis-formation includes almost the 
whole width of the proglottid between the longitudinal nephridial 
canals and is slightly nearer one of the flattened surfaces of the pro- 
Fig. 2: 
Fig. 
oo 
glottid than the other. The region in which the testes appear is com- 
commonly regarded as the dorsal region. 
Before the appearance of the testes the parenchyma in this region 
is not visibly different in any way from that of other regions. The 
large dorso-ventral muscle-cells are scattered through the parenchyma 
but are more numerous midway between dorsal and ventral surfaces 
than elsewhere. Many of them lie in the zone where the testes appear, 
which is of course just dorsal to the middle region where they are 
most numerous. 
In the attempt to determine whether the testes arose from parti- 
Anat. Anz. XXIX. Aufsätze. 38 
