66 - 
Sol lx pedicellarls ?ursh (bog willow) and 
lucida iiuhi. (shining willow)* Two fern species, 
namely Osmund a regalia L. and Aopidium Tholypterls (L.) 
Sw *» often occur at the margin of the water, more or lees 
shaded by the shrubs. Ciianaod aphno calvculata . though 
not the commonest shrub lining the river bank, is pro¬ 
bably the moat important in the formation of floating 
mats, these often starting from sedge hummocks. One 
effect of the mats is to cut off quieter bodies of water 
where various aquatic and amphibious specios are more success 
ful in establishing themselves. 
One thing seems clear in connection with the 
successions along the margin of the river, namely their 
instability. Kven when Carp Lake as such, is gone, the 
river will still continue, though not in its present bed, 
as the bottom of the valley will have been raised through 
sedimentation. 
b. Carp Lake (fig. 1)• 
The lake lies parallel to the main ridges, 
covering the floor of the valley for a distance of about 
2 km. Its broadest portion is near the east end, where 
it has u width of approximately 0.5 km. Excepting at 
this end, the nesophytic foest oxtends nearly to the 
water*s edge. At the east end a broad delta has been 
