Development of the Vegetation of New York State 127 
row sand ridge, doubtless a glacial esker, cuts across the 
shallow valley. Bean Pond lies immediately below this esker. 
(See Fig. 20 which was taken from the top of the esker). 
The “pond” itself appears to be unrelated to the valley 
drainage at present, but below, a narrow strip of lost drainage 
land is occupied by balsam swamp and marsh-meadow (both 
with Sphagnum) and a little farther on the stream finds 
itself in a definite channel. Let us set down serially the cir- 
cumstances here: 
(1) There is the circular, open, almost lifeless zone of 
black water. 
(2) There is no well defined floating Sphagnum-sedge 
zone. 
(3) The Sphagnum-heath shrub mat runs up to the border 
of open water forming the shore line which shows almost no 
evidence of advancing at the present. This mat is compact 
and while leather-leaf is dominant, there are more species of 
heath shrub than at the Tully Lake bog. The shrubs are 
very much dwarfed. 
(4) The encroaching zone of bog forest is made up almost 
exclusively of black spruce. It appears to be in uniformly 
eraded sizes based on age. As a matter of fact, analysis of 
sample strips running radially from the central pond, showed 
that the small trees, apparently almost mere seedlings, near 
the pond are about as old as the tallest ones at the margin 
of the bog. In short there is noteworthy dwarfing of both 
spruce and heath shrub, increasing toward the central open 
water zone. 
It really looks as if the logical outcome of bog conditions 
had been reached in this extreme case; namely, that by reason 
of toxicity, deficit of plant food, acid reaction or whatever or 
what all it may be, the progress of vegetation has been brought 
to a relative standstill. To such a conclusion do the facts 
seem to point, as to absence of floating sedge zone, firmness of 
the Sphagnum-heath mat and of its border on the open 
water; the lifeless, open water zone and the progressively 
intenser dwarfing of spruce and shrub toward this zone. I 
