( 'orrespondence. 255 
continuity and identity to be made with entire safety. Nevertheless it 
seems probable, from similarities of character and from substantial 
horizontality in each of the two groups, that the upper strongly 
developed beaches in the two are really one continuous line. In the 
Jackfish group the highest beach varies from 400 to 430 feet above the 
lake. The higher ground was examined, as well as the extreme rough- 
ness of the country permitted, at each locality. But no evidence of 
higher submergence was found. From Heron Bay, on the Canadian 
Pacific railway, eastward up the valley of the White river to the 
summit at O'Brien, no strand and no lake sediments were found above 
the main beach near Cache lake at about 420 or 430 feet above the lake. 
Missinaibi was also visited. The altitude of this pass across the Height 
of Land was found, by the C. P. R. profile, to be about 75 feet higher 
than the figure quoted by Prof; Lawson. No evidence of a former 
strait was found here nor at Jackfish, which is near the pass to lake 
Kenogami. The upper beach thus appears to be 85 to 90 feet below 
both passes. If the main upper beaches in the two groups of localities 
mentioned are one, it would seem to indicate that instead of rising 
toward the north or northeast, this beach has a very slight declivity in 
that direction. Still, it is very nearly horizontal. If these beaches are 
not one line it seems probable that the one in the Jackfish group is the 
younger and lower. The highest beach descends westward from L'Anse 
on the south shore, and apparently south westward from Mt. Josephine 
on the north shore : and so does the Nipissing beach at a lower level. 
It would disclose a curious history for this basin to find a horizontal 
beach between these two, or one sloping slightly in the opposite direc- 
tion. 
It is hardly to be imagined that there could ever have been a glacial 
or any other kind of barrier between the Jackfish group of beaches and 
Sault Ste. Marie, where the highest beach at Root river is 414 feet 
above lake Superior. The latter is now identified beyond a shadow of 
doubt as the Algonquin beach of the Huron basin, and hence the for- 
mer is probably the same. There is still perhaps a little doubt as to 
the identity of this beach in the western part of the Superior basin. 
Some of the intervals between present points of observation are too 
wide to be bridged by inference with perfect safety. 
These facts completely overthrow the conclusions which I advanced 
in papers published one and two years ago (see last reference above i. 
Throughout my study of the lake region, begun systematically in the 
summer of 1890, I have kept in mind two alternative hypotheses for the 
origin of the highest beaches north of the latitude of Petoskey. First, 
that they were marine and were therefore made by the sea, which 
entered the lake basins ; or, second, that they were made by ice-dammed 
lakes during the glacial recession. The marine hypothesis seemed the 
more plausible of the two. In accordance with it I expected to find 
straits northward from the Superior basin to Hudson bay and high 
shore lines extending eastward from the hills near lake Nipissing to the 
Ottawa valley. All the beaches south of the parallel of Petoskey. how 
