1905] TRANSEAU—BOGS OF THE HURON RIVER VALLEY 429 
species near the borders of the area of geographic. distribution of 
the bog plants, viz., climate. The bog plants of this vicinity come 
into conflict with species whose range is either more nearly continental 
or more southern. That the climatic and edaphic conditions of 
this region are at present unfavorable to the successful competition 
of the bog species with swamp species is evidenced wherever the bog 
conditions have been disturbed. That the reverse is the rule in 
eastern Canada has been shown by GAnone (18, p. 178). The 
tenacity with which species, whose multiplication is principally 
accomplished by vegetative means, hold an area under complete 
control is apparent to any who have studied the vegetation of lake 
shores. It is just as strongly marked in the case of the herbaceous 
and shrubby bog vegetation. When we examine the chemical and 
physical data, now at hand, concerning the soils occupied by bog 
and swamp plants respectively, the conclusion must be that they are 
wholly inadequate to account for the difference in vegetation. The 
forester lays stress upon the fact that trees cannot gain a foothold 
On areas now covered with a grass turf because of the difficulty of 
the seedlings getting started. The bog societies form an equally 
Compact plant growth, and their preservation in this region would 
seem to be dependent upon analogous factors. 
III. The bog-plant societies. 
The following descriptions of local bog areas occurring in the 
Huron valley aim not only to present lists of plants found in this 
Vicinity, but to show their natural associations. The order in which 
the areas are described corresponds to the relative amount of filling 
Which has occurred in the several basins. To a certain extent this 
order is genetic, yet there can be little doubt but that many arctic 
Plants which were concerned in the pioneer stages of our mature bogs 
are Now extinct. If we accept the areas at West and First Sister 
Lakes as representing bogs in youth, maturity may be illustrated by 
the original vegetation of the bog on Carpenter’s road. The Chelsea 
‘rea defines that stage beyond the climax, when the — 
mugurated by cutting, firing, and ditching have destroyed the 
original tamarack forest, and in its place has come a rude mixture 
of bog relicts and arborescent weeds. 
