1918] ROBBINS—BOULDER PARK 515 
The association immediately preceding the present one and the 
future changes are quite clear. The sedge moor is now dominated 
by Carex variabilis and C. utriculata, alternating and freely mixing. 
Obviously, C. variabilis has followed upon C. utriculata. Mosses 
Fic. 13.—Map of Park and Filled Lakes 
are an exceedingly important element in the building up of sedge 
moor. 
If one stands at the old shore line and looks out over the flat, 
sedge-covered lake floor it is seen to be divided into two quite dis- 
tinct parts: (1) the half nearer the outlet is lighter in color, due to 
the predominance of sedges, of which C. uériculata forms a good 
proportion; (2) the north half is darker, due toa pronounced admix- 
ture of Deschampsia, and a greater proportion of C. variabilis as 
compared with C. utriculata. The north half of the lake is drier. 
