118 
Professor Clements has been the descriptive study of vegetation. 
All but sixty pages of the work just cited are devoted to phases 
other than the functional side of ecologv. 
From the time of this work until the present, most of the 
men engaged in ecological work have laid more emphasis upon 
the physiographic side of the subject than upon the individual 
response of plant organs. Transeau, Shreve, Clements, Gleason, 
R. M. Harper, Spalding, Harshberger, Drude, and Cowles, to 
mention only a few, have written papers which, in the main, 
discussed the physiographic features of the science. 
It would be unfair to those mentioned above to infer that they 
have ignored the question of the individual response of plant 
organs to environmental factors as being the controlling agency 
in the occurrence of plant communities. But it may be said, 
with a large measure of truth, that most of them while thoroughly 
realizing the fundamental nature of this proposition, have seen fit 
to lay stress rather upon the physiographic problems than upon 
those of functional and individual adaptations. 
In other words, the term ecology has grown enormously in 
significance since the time of 1897. It has so broadened its scope 
that to-day one of the chief American exponents of the science 
not only maintains that the physiologic and morphologic response 
of plant organs are the main features of ecology, but unlike most 
of his predecessors, he devotes nine tenths of his book to these 
phases of the subject. Professor Cowles, in the introduction to 
his new text book,* has this to say, in explaining the change of 
emphasis: ‘‘Plant ecology has a two-fold aspect: the one con- 
siders the individual organism and its component parts as related 
to environment; this, since it overlaps morphology and physiol- 
ogy may be called morphological and physiological ecology, or the 
ecology of plant structure and behavior. The other aspect con- 
siders plants en masse as related to soil and climate; this, since 
it overlaps physiography, may be called physiographic ecology, 
or the ecology of vegetation.” 
Less than ten pages of the present work are devoted to plant 
* Coulter, J. M., Barnes, C. R., and Cowles, H. C., A Textbook of Botany for 
Colleges and Universities, Vol. II, Ecology, pp. i-x + 105904. figs. 700-1234. 
American Book Со., №. Y. $2.00. [December, 1911. 
