338 
BULLETIN OF THE NATURAL HISTORY SOCIETY. 
appear as plainly as if they were bare. The lack of forest is the 
result of former intense forest fires, which not only cleared a 
part of the south shore of the lake, but produced the extensive 
open dry barrens (Mitchell Plains) extending off a long distance 
to the southward. The surrounding hills show three breaks. 
First there is a low valley extending eastward and connecting 
with that of Portage Brook, flowing into the North Pole Branch.* 
This may be the route of the pre-glacial outlet of the lake valley, 
in which case it would have formed a branch of the pre-glacial 
stream which apparently emptied the Dunn Lake valley into the 
North Pole Branch. This introduces the question as to the 
origin of the east-and-west valley of the lake itself, but this I 
cannot explain, though the fact that it lies in part in a northeast- 
southwest line which includes Dark and Moccasin Lakes** sug- 
gests a possible origin homologous with that of the Upper 
Tuadook and Upper Renous-Indian Stream valleys considered in 
the preceding note. The second break is on the northwest, though 
it is not well marked. It may, perhaps, indicate an early con- 
nection with Dunn Lake in this direction, though such appears 
unlikely. There is some evidence also of a valley directly west- 
ward, and it may be that the drumlin hills of Mitchell Lake re- 
present the finer glacial debris washed by this route from the 
Gover Lake Basin, in which all the glacial material is very 
coarse. The third break is to the southwest, followed by the 
present outlet. The entire country crossed by this stream is flat 
and open, evidently an extension of the Gover Lake Basin. The 
stream flows with but moderate fall over drift, — in its upper course 
over boulders and in its lower course partly over gravel, — but I was 
unable to find anywhere along it any clear evidence as to whether 
* I have not yet been able to visit the North Pole Branch, but Mr. Braith- 
waite’s description of it as, for the most part, a fine canoe stream, would indicate 
that it occupies a very ancient valley. The maps show a great bend in the river 
just below where Portage Brook enters it ; it is very likely this bend represents a 
post-glacial course, while the pre-glacial course is directly across the bend, a 
subject I hope later to be able to study, especially as its head waters also offer 
some curious problems. 
** Dark (Birch) and Moccasin Lakes are both attractive (especially the lat- 
ter) forest encircled lakes. Reeds Lake, much more elevated, is apparently shal- 
low and with low shores, but is said to contain large trout. 
