Tt The New York State College of Foresiry 
plains lie well above the water table and are subject there- 
fore to extreme drying. In such cases the vegetation is of 
the dry heath types. In the case of Grasse River bog, the 
sand plain lies so low that if one could see the original sand 
bed, now of course covered by its peat blanket and the living 
vegetation growing thereon, it would be seen to be covered 
by water much of the season, emerging only during dry periods 
of midsummer. Thus, in August, 1918, and again in 1919, 
borings in the shallower parts of the bog showed no free water 
at the sand level, though, of course, the peat was wet. In 
October of the same season, nearly all of this sedge meadow 
part of the bog was flooded. This relation to the water table 
insuring constant wetness is the primary cause of the bog 
vegetation as contrasted with the characteristic dry heath type 
of the better drained sand plains. 
As above stated, the Grasse River bog lies in_ part 
along the course of the upper Grasse River where this 
small stream emerging from narrow valleys in the hills follows 
a slowly meandering course acress the sand plain, and eseapes 
through a narrow gorge with rapids at Shurtleffs. (Fig. 1.) 
It is somewhat as if a lake had been interposed in the river’s 
course, and with but a few feet less of cutting in the gorge 
at Shurtleffs this would actually be the case. A low, temporary 
dam at the latter point makes still water as far up as Burnt 
Rock — about two miles. This is the Grasse River Flow. 
The stream has done very little cutting through this portion of 
its valley —i. e., the bog—in post glacial time, its actual 
channel being a low banked sinuous cut with a flood plain of 
only a few hundred feet in width. The sand plain itself is not 
merely river valley. It occupies a peculiar relation to a series 
of ponds and lakes Iving along its eastern and northeastern 
margin. The largest of these, Massawepie Lake, represents a 
basin of considerable maximum depth, said to be more than 
100 feet, whose southwest shore line is the border of the bog 
itself. -.( Fig: 3.) 
The outlet of Massawepie Lake skirts the northern edge of 
the hog being almost flush with its surface, escapes through 
