16 Canadian Record of Science. 
I purpose at an early day, illustrating these British Colum- 
bia groups more fully. 
SuB-ARCTIC GROUP. 
The Labrador current, which, laden with icebergs, des- 
cends from Baffin’s Bay, and in a broad stream of three 
hundred miles, skirts the Labrador coast, sends an off-shoot 
of its waters through the Straits of Belle Isle, and past 
Anticosti, up the northern side of the estuary of the St. 
Lawrence. Meeting, as it proceeds upward, the warmer 
fresh waters of the river coming from the Great Lakes 
above, this branch current is diverted to the south coast of 
the estuary, where it appears as a stream, cold, but some- 
what warmer than on the north side, and, proceeding on- 
wards, finally leaves the coast at Gaspe. The effect of this 
cold current on the vegetation of the shores, is seen in the 
occurrence of a few arctic and many sub-arctic plants at the 
Straits of Belle Isle and on Anticosti and the Mingan 
Islands, and occasional sub-arctic species as far up on the 
north shore as Tadousac and Murray Bay. Even on the 
Island of Orleans, near Quebec, there are some boreal forms. 
The flora of the south shore of the estuary shows the milder 
character of the current there, whilst that of the Bay of 
Chaleur appears to prove its comparative absence in that 
locality. 
On the jutting headlands of Lake Superior, and along the 
bays of its northern coasts, there are both sub-arctic and 
boreal plants, which appear to form an isolated group there. 
It is not difficult to account for their continuance in these 
localities. Northern species delight in a low, equable tem- 
perature and a moist atmosphere, and whether this is 
obtainable on alpine summits or on sea or ocean coasts, 
there they find a congenial home. The high northern shores 
of Lake Superior supply these conditions. To account, how- 
ever, for their original presence there, it is necessary to go 
back to glacial or post-glacial times, when, with a some- 
what colder climate, and with the area of the Great Lakes 
forming the bed of an inland sea, some sub-arctic and boreal 
plants found a natural highway along the coasts of this 
