1903] VEGETATION OF THE BAY OF FUNDY MARSHES 451 
lated, while physiological adaptation, the study of the 
accommodation of the protoplasm itself to outside influences, 
has received little attention. Yet this is the most important 
subject of all in adaptation; for structure, so far from represent- 
ing the important feature in the adaptation of the plant to its 
environment, is simply an external manifestation of the way in 
which the protoplasm brings itself into better touch with the 
environment. It is an expression of a degree of physiological 
properties, and it is the properties and powers of the protoplasm 
itself which is the important thing. All such data are essential 
to the full understanding of the real nature of the vegetation- 
forms, those units of the ecologist; and in this direction, 
viz., the determination of physiological life histories of important 
plants, there lies not only an indispensable approach to future 
advance in ecology, but a most attractive field of research for 
its own sake. Such studies, and such only, will enable us to 
understand the true natural history of individual plants, and will 
help to bring the day when our “manuals,” in addition to giving 
us the details upon which the classification of our plants is based, 
will give us also such information about their lives and habits as 
will enable us to understand their places in nature. These 
Studies may in part be followed in university laboratories, but 
for the most part they can be carried on only in field labora- 
tories, such as have already been mentioned as needful for the 
Study of physical problems, and here both classes of problems, 
similar in general methods and inseparable in results, can best 
be investigated together. 
Fourth, a knowledge of the true nature of plant competition 
and cooperation is ‘essential. The fullest knowledge of the 
physical environment, and of the power of the plant to respond 
to it, would only enable us to explain the general situation and 
vegetation-form of plants in cases where each individual was 
free from any interference from others. But in fact, as we 
know, plants are rarely or never so situated, for, massing 
together, they profoundly affect one another’s distribution and 
form. The study of vegetation, therefore, of masses of plants, 
involves this important element of their effects upon one 
