[PENHALLOW] DEVELOPMENT OF CERTAIN MARSH LANDS 33 
numerous small, fresh water basins have been formed in precisely this 
manner. They do not receive a very large drainage, and in the absence 
of special outlets, the normal water level is maintained wholly by 
evaporation and seepage. These basins have gradually become occupied 
by fresh water vegetation, and at the present time they present most 
instructive examples of bogs in all stages of development from open 
ponds with a shore fringe of sphagnum to “quaking bogs” and bogs 
which are rapidiy becoming converted into useful meadow lands. With 
such examples close at hand, it is impossible to avoid the obvious con- 
clusions to which they point. 
The subsequent history of the two ponds seems to be essentially 
identical up to a very recent period, with the exception of certain differ- 
ences in drainge due to change of level incident to continued subsidence. 
The overflow of the, Sea Point pond into Chauncey Creek, served to 
establish a permanent channel which was only partly closed by the later 
growth of vegetation, and this because of the insurmountable obstacle 
- interposed by the two barrier beaches; but this channel remains to-day, 
the only outlet for this area, while it is also the only means by which 
the salt water may enter and flood it. 
In the case of the Brave-Boat Harbor pond, the overflow was to 
the southward into Chauncey Creek, but this narrow and shallow channel 
soon became clogged with vegetation and eventually closed altogether, 
in consequence of the fact that the formation of soil and of a retaining 
turf proceeded much more rapidly than the rate of subsidence. The 
consequent damming back of the accumulating water at the natural point 
of egress, together with the large accessions continualy received from the 
drainage area to the west, caused an overflow of the barrier beach and the 
cutting of an “inlet” after the manner described for such formations 
But for a long time before such an “inlet” was developed, the pond 
passed through a long period of transformation which was in all respects 
the same as in the Sea Point pond, with respect to the development of 
a typical bog. 
In both ponds the change was initiated by the formation of 
sphagnum which, gradually extending out from the shore line, 
eventually came to occupy the entire water field. Fresh surface 
accumulations of this plant forced the earlier growth to a lower level, 
and in course of time the marginal portions came to rest on the bottom 
while the central portions were still floating. Increasing pressure of 
the augumenting mass, combined with decay of the under layers, would 
operate to convert the whole into peat, and it is altogether probable 
that an exploration of the shore regions would bring to light an abun- 
dance of well formed peat. But in the central area where special 
