Diseases of Fish inthe Adirondacks 25 
determined, these bodies appear to be of growing larvae but as yet 
the cells are not arranged into organs. [| have found these cysts in the 
muscles as late as October 21st. An attempt is being made to study 
these conditions throughout the winter and early spring. I expect to 
find that these cysts remain in the muscles all winter and during the 
early spring transform into the large worms with their well known 
cysts. 
Original by W. M. Smallwood 
Figure 11. Older cysts from muscles of perch in which the several 
layers in the wall of the cyst are present and the larval worm has 
a clearly defined digestive and reproductive system. The presence 
also of the oral and ventral suckers clearly indicates that these are 
early stages of Clinostomum marginatum. In the large one the cyst 
is 1.1 mm. long, .6 mm. wide, as compared with 3.5 mm. long for those 
described by Loess. The larval worm being .72 mm. long and .4 mm. 
wide. Small specimen has a cyst .8 mm. long, .5 mm. wide. Larval 
worm .65 mm. long, .35 mm. wide. Original. 
