Development of the Vegetation of New York State 25 
in that period and which made the land surface a highly dif- 
ferentiated habitat for plants. 
3. As To the Nature of Vegetation. 
The city is not merely a census figure. No more is a for- 
est a list of plant species. The State is not merely a mass of 
people, far less an unorganized mob. No more is vegetation 
a mere mass or unorganized mob of trees, shrubs, ferns, 
mosses and so on. In each there is a certain biological order- 
liness, a biological stratification if you will, (in the State, of 
course, social, political, ete., as well) and especially in each 
is the forward mass movement or development an orderly 
thing and from a simple or pioneer beginning to the complex 
or more highly differentiated condition. When you think of 
it, the crowding of plastic (adaptable) organisms on the 
earth’s surface (and consider the reproductive energy of 
species) must entail mutual adjustments which would ulti- 
mately mean orderly or organized association as contrasted 
with haphazard crowding. 
Now the high forest such as we have in New York State 
— what we are calling here the climax forest because as a 
matter of fact it is the high tide of vegetation development — 
is an orderly thing. It is in reality a social organization or 
complex organism. You can’t get it on bare rock nor (absur- 
dity!) at the bottom of a lake. Not on bare sand nor in a 
swamp. Nevertheless, you can start the course of develop- 
ment at any of those stages (in the case of a lake of course 
only on bottom to which enough light energy penetrates for 
the constructive work of green plants) and arrive in the 
course of time at the complex stage of a forest. But the 
pioneer stage of the lake bottom would be a simple associa- 
tion of a few species of similar adaptations to the habitat — 
Potamogetons, Elodea, Naias. In the course of time, partly 
by the accumulation of dead vegetation, partly by mineral 
sediment, the lake bottom is built up to mere shallows. This 
permits a wider range of species and among others those 
like water lilies having floating leaves. Thus a new associa- 
