of Edinburgh, Session 1882 - 83 . 
221 
tory passage has been noticed. Possibly they lead by very minute 
openings into the oesophagus itself, and perform the function of a 
salivary gland. 
The intestine or stomach, for the alimentary canal presents no 
division into these two parts, has a straight antero-posterior course, 
and terminates by a narrow rectum at the hinder extremity of 
the body. Two mesenteries, not diametrically opposite to each 
other, but separated by an angle of 90° to 120°, pass from the body 
wall to the intestine, enclosing also two large glandular bodies 
(“ Ilahendriisen ” of Leuckart) which lie one on either side of it. 
The testis is a long thin-walled dorsally-situated sac, as described 
by previous observers. Towards its anterior extremity the lower 
wall presents a thickening in which two grooves are formed, whose 
walls arch over, and convert them into two tu bes, the vasa deferentia, 
which subsequently become united, and then separate again. 
Their course is now round the intestine, one on each side, passing 
through the “ Hakendriisen,” until they reach the ventral aspect of 
the body, where each becomes connected with the excretory appa- 
ratus of its own side. 
The genital apertures lie side by side a short distance behind the 
mouth, and each leads into an oval sac, to all appearance the homo- 
logue of that which contains the cirrus in P. tcenioides, except that 
in the specimens examined it was quite empty. 
From the dorso-lateral side of this sac, on which aspect its 
wall is very much thickened, two tubes are given off, one anterior 
and one posterior. The anterior tube enlarges, soon after its com- 
mencement, to form a small spheroidal chamber, and, subsequently 
contracting, passes backwards, extends some distance behind the 
sac, and terminates blindly after a course of three or four milli- 
metres; the end of it is variously coiled. 
A little anterior to the middle of this tube the vas deferens 
comes into contact with it, the walls of the two fusing, but the 
lumen of the vas deferens is not continued beyond this point ; it 
terminates blindly. 
The truth of this observation, so exactly opposed to what might 
have been expected, has been confirmed by the preparation of a 
very careful series of transverse sections, which show the one tube 
lined with a perfectly smooth layer of epithelium, passing by 
