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1907] BRIEFER ARTICLES 341 
THE ORGANIZATION OF THE ECOLOGICAL INVESTIGA- 
TION OF THE PHYSIOLOGICAL LIFE-HISTORIES 
Upon several occasions I have expressed the belief that the first need of 
plant ecology is the determination of the physiological life-histories of the 
forms concerned. I propose now to explain more fully what I mean. 
First, it is essential to note our changing conception of ecology. It is 
not long since we sought a use for every detail of plant structure and 
habit, and, correlatively, assumed that these had been developed in some 
kind of causal touch with the environmental conditions they were supposed 
exactly to fit. This was causal, or historical, adaptation, and it was the 
logical product of the Darwinian assumption of a struggle for existence so 
keen as to make even minutiae determinative of the survival or extinction 
of whole organisms, and through them of entire species. Now, partly 
because of the work of DE Vries, but partly, I venture to assert, because 
of the studies of ecologists themselves, we are ceasing to require utility in 
details of structure and habit, and are coming to believe that such details 
may be determined by factors wholly independent of the immediate envi- 
ronment. This newer view does not exclude the possibility of causal or 
historical adaptation in details, but it accepts the probability of a very 
different origin and meaning of those details. And this different non- 
causal origin and meaning of the relation between the details of structure- 
habit and environment may be either of these two. First, the adaptation 
may be real but a matter of accident or coincidence, the details arising 
from internal or other irrelative causes and finding their appropriate 
environment by a process of sifting. Second, the details, however arisen, 
may have no positive relationships whatever with the environment, but, 
not happening to run counter to any very potent feature of that environ- 
ment, they exist by toleration. In brief, while adaptation as a broad, a 
general, a generic matter is a reality and rests upon a certain historical or 
causative basis, adaptation as an exact, a minute, a specific matter Is quite 
different; it may be causative, but it is more often coincidental or tolera- 
tive. The ecology of the future will be, primarily, not a search for utilities, 
but an analysis of meanings. 
I emphasize this matter thus fully because I believe that in the phase 
of ecology of greatest present-day interest, viz., physiognomic ecology, the 
study of the factors determining the features of vegetation, it will prove 
most illuminating. A great deal of our supposed adaptation of vegetation 
t Read before the Botanical Society of America at the New York meeting, Decem- 
ber 29, 1906. 
