io College of Foresiry 
as held by Osborne ’1r. Perch packed in moss and expressed from 
Lake Clear, N. Y., to Syracuse, in the middle of September, 10913, 
contained about ten parasites each, but on arrival more than two- 
thirds of them had escaped from the body of the dead perch and were 
themselves dead in most instances. They were found on the skin of 
the perch (completely extended). But not all of them had emerged 
and those still encysted in the muscles were alive when released. 
Examining the perch it was easy to discover where the parasite had 
crawled out. Those in the cyst were about ready to escape because in 
many instances when the whitish spot was pressed upon the parasite 
would emerge. The walls of the cyst and the muscles immediately in 
contact with it were partly dissolved indicating that Clinostomum 
has the power to cause the walls of the cyst, the surrounding muscles 
and overlying skin to disintegrate. This would seem, moreover, to 
be a natural process but is one that was not observed to take place 
during the summer when dead perch were kept several days.* This 
may be the normal process employed by the worms in the fall to free 
themselves from the perch, as fish free from parasites are found in 
the winter and early spring. Certainly this method of escaping throws 
new light on their habits and suggests that fish-eating birds are not 
necessary to complete their life history. For parasites probably do 
not make their escape in the fall until after most of the birds that 
feed upon perch have migrated, and even if the birds had not migrated 
there would be small chance of the parasites being eaten after they 
reach the water. But where and how the adult Clinostomum, its eggs 
or larvae spend the winter is unknown at present. 
ae 
One often hears the guides say that the perch become “ grubby” as 
soon as the water warms up in the spring. All of the ponds examined 
thus far are spring-fed and into some a cool brook empties or on the 
shore one Or more springs are to be found. This is particularly the 
case at the upper end of Copperas where several springs are to be 
found, the water of which many campers have enjoyed. At the foot 
of a large tree a splendid spring runs into Copperas and some of 
the worst infected perch found during the summer were taken from 
the shore while standing beside this spring. Wells driven six or eight 
feet deep on the islands in Follensby Clear supply campers with plenty 
* This same phenomenon was again observed May 28, 1914. This 
time the parasite escaped within an hour after the fish were caught. 
I believe that these parasites had remained in the flesh of the perch 
all winter. 
