SEA-FISHERIES LABORATORY. 285 



walls may be connected together by a fibrous tissue, which 

 appears to be continuous with the walls of each cyst. 

 Within the cyst the interspaces between the parasites are 

 filled up by a very peculiar tissue (fig. 16), which, on 

 examination with a high power lens, is seen to be made 

 up of small corpuscles of variable diameter — 2*8 to llyot, 

 average about 7/x. They have a fatty appearance, being 

 comparable to cells, in which large vacuoles of some non- 

 staining material are being formed. The small corpuscles 

 are very dense, vacuolation being absent or nearly so, and 

 they stain a uniform red with Mann's methyl-blue-eosin 

 combination. The larger they are the greater become the 

 vacuoles, and the smaller the amount of the original red- 

 staining substance. The staining reaction is now blue. 



Eggs which have been extruded by the parasites are to 

 be found among these corpuscles, and some of the latter 

 may occasionally be seen within the alimentary canals of 

 the former. 



The trematode itself is represented in fig. 2, PI. III. 

 The body is pear-shaped. At the anterior extremity there 

 is a widening of the body forming a kind of collar. The 

 anterior sucker is sub-terminal, is large and oval. The 

 oral sucker is small, and is situated well back behind the 

 middle of the body. In some specimens, cut longitudi- 

 nally in section, in situ, the pharynx is even further back 

 than in the specimen figured. The cirrus is large, and 

 extends forward in front of the pharynx. The uterus 

 is very voluminous, and in some specimens fills up the 

 greater part of the body, preventing the other organs from 

 being seen ; it is full of eggs. The testes are large, and 

 are situated anteriorly to the pharynx. Titellaria are 

 difficult to see, but consist of about half a dozen rounded 

 masses on each side, well in front of the testes ; the ducts 

 of the testes cannot be traced with certainty in any of the 



