184 UNSEGMENTED ‘“‘WORMS.” 
are two suckers—an anterior, perforated by the mouth; 
a second, imperforate, a little farther back on the mid- 
ventral line. 
Fic. 95.—Structure of liver fluke.—After 
Sommer. From ventral surface. The 
branched gut (g.) and the lateral 
nerve (/.z.) are shown to the left, the 
branches of the excretory vessel (¢.v.) 
to the right. 
m., Mouth; 4/., pharynx; g., lateral head 
ganglion; v.s., ventral sucker; ¢.s., position 
of cirrus sac. An arrow indicates the ex- 
cretory aperture, 
Thence they are expelled by an ejaculatory duct, which le 
» muscular protrusible penis. The retracted penis an 
There is a muscular 
pharynx and a_ blind 
alimentary canal which 
sends branches through- 
out the body. The 
food is the d/ood sucked 
from the liver of the 
host. From a ganglion- 
ated collar round the 
pharynx, nerves go for- 
ward and_ backward; 
of those which run back- 
ward, the two lateral are 
most important. Al- 
though the larva has 
eye spots to start with, 
there are no_ sense 
organs in the adult. 
The body cavity is not 
represented unless it be 
by minute intercellular 
spaces in the body par- 
enchyma. Into these 
there open the internal 
ciliated ends of much- 
branched excretory 
tubes, which unite pos- 
teriorly in a_ terminal 
vesicle opening to the 
exterior. 
The reproductive system is. 
hermaphrodite and complex. 
From much-branched testes, 
spermatozoa pass by a pair of 
ducts (vasa deferentia) into 
a seminal vesicle lying in 
front of the ventral sucker. 
ane through 
the seminal 
