Development of the Vegetation of New York State 97 
great activity in vegetative propagation which is associated 
with the capacity of such vegetation to form the heavy banks 
or beds above referred to. Thus a large proportion of the 
shallow bottom of Oneida lake — for example the whole 
area of Big Bay — is occupied by Potamogetons. The most 
noteworthy case which has come under my observation is 
that of the invasion of Tully lake and the adjacent Crooked 
Lake bottoms by Hlodea. Beginning with an insignificant 
occurrence, within a period of some six years this plant has 
come to occupy most of the lake bottom (except in certain 
shallows) to the depth of twelve and even fifteen feet. The 
luxuriant growth and branching build up beds eight to ten 
feet thick which where they reach the surface of the water 
materially impede the movement of rowboats. In this case 
Potamogetons are largely excluded from situations formerly 
occupied by them exclusively. 
The amount of lake bottom covered by this type of vegeta- 
tion is affected by several factors — the physical character 
of the bottom to begin with — but in general by the depth 
and transparency of the water. In the case of Big Bay in 
Oneida Lake a uniformly shallow bottom is wholly occupied 
by it. In Tully Lakes where there is a series of shallows 
and deep basins, Potamogetons, formerly the dominant 
growth, occur in banks occupying the sloping margins of 
the basins from a few feet to twelve or more feet in depth. 
In these lakes there are also lake bottom flats similarly 
covered but now yielding to Hlodea. In Conesus lake —e. ¢., 
off Old Orchard point —where the bottom falls away to 
considerable depth, Potamogetons and other aquatics form 
a zone from the depth of eight or ten feet to a maximum 
of sixteen or eighteen feet. The so-called ‘ island,” a sub- 
merged flat under twelve or more feet of water is occupied 
by Potamogetons. This represents perhaps the general status 
in waters of average clearness. In the Adirondacks however, 
especially in the smaller and shallower lakes, the dark color 
of the water due to humus leachings from the adjacent forest 
soils appears to operate in excluding light — possibly chem- 
ically also ?’— and thus in limiting this type of vegetation. 
