Forest Development in the Adirondacks 45 
herbaceous species followed by a close willow-alder association 
which is progressing toward the (presumably) balsam swamp 
forest which has relatively recently been destroyed by human 
agency. This situation in its early vegetation stages appears to 
be intermediate between the wet heath of the low lying 
undrained sand plain and the dry heath illustrated by the 
Oswegatchie sand plain. 
6. A third feature of the region here dealt with, consists 
of the flood plain of the Grasse River which by reason of its 
better drainage and its deep alluvial soil exhibits a lvely con- 
trast with the bog in its total lack of sphagnum, its early 
association of Calamagrostis and associated species forming a 
typical beaver meadow (ecologically a typical marsh meadow) 
and a vigorous invasion (checked in certain places by annual 
mowing) of alder thicket. It is regarded as not unlikely 
that this flood plain may in earlier times have been covered 
by balsam swamp forest and the assumption is made and 
strengthened by observations elsewhere in the vicinity that the 
normal course of vegetation here would be toward this type 
of forest as its edaphic climax. 
7. The living sphagnum cover of the bog (ecologically the 
sphagnetum) is composed of a number of species of sphagnum 
differing in habits of growth and in light and moisture require- 
ments. Thus certain species are predominant in different 
stages of the vegetation sequence, e. g., in the open sedge 
meadow and forming the climbing growth among shrubs, in 
the shade of old conifer bog forest, and on the drier tops of 
mounds in the uneven surface of the heath shrub associations. 
€, The actively functional roots of vascular bog plants are 
distributed in the superficial zone of newly formed peat, the 
dead but not disintegrated sphagnum and the hving sphagnum 
cover. Apparently they do not penetrate the underlying sand 
in the case of any species. 
9. Vegetative propagation is almost universal among bog 
plants. Vegetative propagation by sphagnum reaily forms the 
basis and controls the method of bog evolution. The sub- 
stratum created by it stimulates active production of roots and 
