64 postelsia 



these conditions no extensive development of 

 hijj^her forms of vegetation is to be looked for in 

 their clear, cold waters. Aside from various 

 species of algae, only a few Bryophytes like 

 Hypunui and Foiiliiutlis are of general occur- 

 rence. In occasional pools, Callitrichv palustris 

 is met witli. 



3. Lake beach formation 

 Vancouver Island i)ossesses a number of lakes 

 the largest of which is Cowichan with over 20 

 miles of water expanse. Most of the lakes, 

 however, are of the character of mountain tarns. 

 Of those Iving in Renfrew district, only I>ake 

 San Juan was \isited 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 completelv 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 10 and 15 meters. One meets here 

 with the peculiar condition of a far northern 



