Nos. 618-619] RESTOCKING INLAND WATERS 



347 



itself contains numerous blood corpuscles, as if they had 

 been emptied into the cyst. The difficulties of fixation 

 have prevented me thus far from studying the character 

 of the blood in these cysts. 



As the cyst grows, the wall of which is made up of con- 

 nective tissue, partitions are formed which grow in from 

 the main outside wall. The result is that in the older 

 stages three to five separate cavities are found in each 

 cyst (Fig. 6), although but a single larval Trematode is 

 present in each cyst. I have opened a large number of 

 these cysts and thus far have found no exceptions. 



Not much can be said at this time in regard to the struc- 

 ture and changes through which this larva is passing. 

 That it is growing there can be no doubt, as different 

 stages showing the presence or absence of some of the 

 mature organs were found. In most of the whole larvae 

 dissected and mounted, the excretory ducts are com- 

 pletely formed, while the digestive tract is limited chiefly 

 to the anterior end. Two suckers can be recognized and 

 a part of the reproductive organs. The whole animal is 

 so very small that it can scarcely be seen with the un- 

 aided eye. It will require better fixation before the spe- 

 cies can be determined accurately. I am inclined to 



