152 BULLETIN UNIVERSITY OF MONTANA 
Pass it would be to a stream leading into Clarke’s Fork through Missoula, 
where it has not been seen. 
It is hoped soon to make an expedition to the headwaters of the Big 
Blackfoot and Swan rivers, when the question may be settled. 
Few water birds were seen on the lake. It does not seem to be a 
favorite resort for them. Although there are several species of fish 
they do not seem to thrive in the warm waters of the lake. It is pos- 
sible later investigations may show this to be a good breeding place, as 
Entomostraca are quite abundant. Other forms of animal life, such as 
larval Diptera and Odonata, leeches and worms have not been determined 
except in case of adult dragonflies. 
Plate XLIV is a good view of this very interesting lake. The pho- 
tograph was made from the bridge at the outlet. The view 
is northeast, up the lake. In the foreground is a bed of pond lilies. 
Rushes almost choke the stream. The dense vegetation along the shore 
line is plainly discernible. The wooded valley is a great shelter for 
white-tailed deer. During ten days stay in the region not a day passed 
without some one of the party either seeing or hearing an animal. Bear 
are abundant in the hills. 
In the hills east of the lake mountain goats are reported. In former 
years an occasional moose is said to have reached this region, though none 
are now seen. Their spoor is found in the mountains shown in the back- 
ground. Elk and black-tailed or mule deer were also formerly taken in 
this region. The former are no longer seen, and the latter only occa- 
sionally. But the white-tailed or Virginia deer roams the forests in the 
summer from the settlements to the summits of the range, altiude 7,500 
feet. They have been seen on the snow banks almost at the summits. 
They are fond of lying in the open places on the high ridges in summer. 
Here they escape in part from their worst enemies, the flies. Food is 
abundant. They bask in the sun, rarely disturbed by man. 
It was stated that the borders of Rost lake contained many sphagnum 
bogs, mud holes and swamps. In July we traveled miles of meadows and 
bogs with scarcely a dry knoll during the entire distance. In these 
marshes, which are no doubt deep in early spring, there must be an abund- 
ance of smaller life. 
Among the interesting features presented by a brief stay at this lake 
was the information that all the deer were badly infested by a liver fluke. 
Numerous reports came regarding the “bloodsuckers” that were in the 
liver of every deer, etc. Coming from reliable sources these stories 
could not be denied. The first specimen examined after hearing these 
reports had two large flukes encysted in the liver. Old residents make 
the statement that “when you kill a big cld buck in the fall, take out his 
liver and shake it, it is so rotten with blooksuckers it falls to pieces.” 
The life hisory of this fluke will be an interesting study for some one. 
From the shells thus far found the early stages are likely to be in a 
Physa, although Planorbis trivolvis should be present in the region. 
Next to Daphnia pond Rost lake has greatest interest for students at 
the Biological Station. 
