61- 
saplings mixed with white hi rah aro not uncommon (fig.40). 
The appearance of many other woody species is due more to 
the itncreased moisture along the margin of the flood plain. 
Among these may he mentioned ffraxinus nigra Marsh. (black 
ash), Sal lx dipooler Kuhl• (glaucous willow). Viburnum 
Opulus L. (cranberry-tree), nlmus inoana (L.) Moench. 
(speokled alder), .acer rub rum L. (red maple), Spiraea salici - 
folia L. (meadow-sweet) and Cornus stolon! for a Llichx. (red- 
osier dogwood). 
l'he complex of ibrost and flood plain species is very 
variable in its composition. This may be explained partly 
by the very unstable conditions in the valley and partly 
by ohanges in the edaphio conditions produced by gullying 
down the side of the rungo, with the consequent deposition 
of new soil near the bottom of the slope. A noteworthy 
instance of the latter occurs opposite the saddle in sec. 
14 (fig. 41). Gullying in this case is due to the in¬ 
creased drainage over the saddle, resulting mainly from 
the melting snow in the spring. In the summer, its upper 
portion at least may be dry. 
II. Hydraroh successions in the valley of Carp River. 
As before indicated, the mesophytic forest be¬ 
low the talus slope is bordorod by Carp River or its flood 
plain. This flood plain is comparatively broad in the 
