Bickett—The Larger Aquatic Plants of Green Lake. 389 
In a few stations there is no flattening out from 1 to 6 meters, 
but the bottom drops steeply beneath the water (Stations 16 and 
30). In these cases the vegetation extends only to 4 or 5 meters 
beneath the surface. This condition is represented in figure 7. 
Fig. 7. Diagram of portion of lake floor bearing attached plants. Steep 
slope. 
There is a certain degree of correspondence between the type of 
shore, the slope of the lake floor, and the vegetation. The type of 
slope represented in figure 5 is the most common, and is found 
opposite rocky shores of all sorts, such as those shown in figures 
1 and 2. The steeper the shore, the steeper the slope of the bottom. 
The second kind of slope (figure 6) corresponds to low shores, 
either marshy or sandy (figure 3). The last type (figure 7) is 
found only opposite high land, such as Lucas Bluff and Sugar Loaf. 
In Mendota it was found that there are well-defined patches of 
sand in various places, running into fairly deep water; and that 
some species were more or less limited to a sandy substrate, others 
to a muddy one. No such differentiation exists in Green Lake. 
The type of bottom is fairly uniform; it consists of a fine mud 
mixed with marl in deep water and with a small amount of sand 
in shallow water. The most important difference between stations 
is the presence or absence of rocks. Yet there is great regional 
variation in the vegetation, and although this cannot be correlated 
with any visible soil difference, it is probable that chemical analysis 
of soil from different places would tell a different story. In the few 
places where there are distinct sandy beaches, such as are more 
common in Mendota, these are not nearly so well covered with 
