40 BOTANICAL GAZETTE [JANUARY 
all abundant, and by P. zosteraefolius, which is also sparingly pres- 
ent. The open water is 18 (5.4™) deep in the deepest place, 
which is near the south end. The bottom is of blue clay with a 
very thin film of black organic matter resting upon it. This 
clay bottom is derived from eroded material that has washed 
into the lake, chiefly before so much peat had accumulated 
around the borders of the basin, the finest of which, in turn, has 
been washed out into the middle of the lake and has settled in 
the deepest water. A section of the lake opposite the ice-house 
( fig. 2) shows that it is a flat-bottomed, saucer-shaped basin. 
Fic. 2.—Section through lake opposite ice-house. Scale 1 : 900. 
As we approach within 50 to 60 (15-18™) of the shore we 
come to the rather steep incline of the terrace formed by the 
border vegetation. This is composed of dead organic material — 
in which sphagnum is conspicuous. Even though the lake is 
small, the waves probably stir it to the bottom, as it is so shal- 
low. The water is highly colored, a yellowish-brown, by the 
decaying organic substances, and. contains much solid matter in 
suspension, 
2. Nuphar zone. The terrace just described is occupied by a 
very prominent and almost unbroken zone of yellow pond lilies 
from 20 to 30" (6-9™) wide, growing in water from 6” to 
5-5" (15-167) deep. It is widest in the quiet water of the 
southwest end of the lake, while on the east there are a few 
short spaces where it is interrupted altogether; but on the whole 
it is analmost perfect zone. These lilies are most efficient agents 
in reclaiming a lake. Not only can they creep out with their 
stout rootstocks into 6 (2™) or more of water, binding together 
