140 PLAT YVHELMINTHES. 
meet to form a median vitelline duct. This runs forward 
to meet the ovarian duct and from their junction there 
passes a median dorsal tube to the exterior, the so- 
called vagina. The junction is surrounded by a round 
shell-gland which secretes the shells of the eggs, and the 
united ducts lead towards the anterior end as a much-coiled 
oviduct. This opens to the exterior in the median ventral 
line between the two suckers. 
Fig. 72.—View oF LIVER-FLUKE (Diéstomum). 
Showing the Reproductive Organs. (After SomMER.) 
Common 
Genical Aperture. 
Seminal 
Vesicle. 
Vas Deferens. 
Ovary. 
Oviduct. 
Vitelline 
Gland. 
Left Testis. 
Shell Gland. 
Vas Deferens 
(leading to 
\ : Laurer’s Duct. 
right testis). 
Vitelline Duct. 
The male organs consist of a pair of branched “estes, 
one behind the other. The vasa deferentia from them 
