60 Postelsia 
Tiarella trifoliata Boykinia elata 
Tolmiea menztesit Mitella ovalis 
Viola glabella Moneses uniflora 
Mimulus moschatus Galium triflorum 
2. River bed formation 
a Banks and Channer 
Gordon River Bed—WDuring the summer 
months, the volume of the river decreases to 
such an extent as to leave exposed the banks 
from where the forest and its underbrush ceases, 
and also a considerable extent of the boulder 
strewn channel bed. ‘Two types of river banks 
can be distinguished here, viz; moist sandy 
banks and moist rocky banks. Both kinds are 
more or less shaded by the overhanging branches 
of the adjacent trees, yet it is self evident that 
much more light is admitted here than into the 
forest of the slopes on either side. 
Upon the sandy banks are associated a few 
species, no one of which figures predominantly 
and all growing more or less scattered or in 
tufts. In this scanty society are most gener- 
ally to be observed: 
