64 Postelsia 
these conditions no extensive development of 
higher forms of vegetation is to be looked for in 
their clear, cold waters. Aside from various 
species of algae, only a few Bryophytes lke 
Hypnum and Fontindélis are of general occur- 
rence. In occasional pools, Callitriche palustris 
is met with. 
3- Lake beach formation 
Vancouver Island possesses a number of lakes 
the largest of which is Cowichan with over 20 
miles of water “expanse. Most of the Wakes 
however, are of the character of mountain tarns. 
Of those lying in Renfrew district, only Lake 
San Juan was visited and the vegetation in and 
around it studied. This is a small body of 
water situated a few miles inland and off to one 
side of the valley bearing the same name. The 
lake is almost completely surrounded by high 
hills, its waters finding outlet into San Juan 
river through a narrow rift in the surrounding 
barrier. Its level above sea was not definitely 
ascertained but a rough estimate would place it 
at between ro and 15 meters. One meets here 
with the peculiar condition of a far northern 
