258 SECTIONAL ADDRESSES. 
‘adapt itself ’ during its development to its conditions of life. That is 
to say, it does and must react to the forces, external and internal, acting 
upon its several parts, and the result of the reaction must be to bring 
it into closer equilibrium with the whole of those forces. It is some-' 
times forgotten that ‘ adaptation’ in this sense is a wide physical con- 
ception which does not imply that the whole of the characters of an 
organism are ‘useful’ to it in the sense in which all the parts of a man- 
made machine are useful. 
Thus we conclude that the central and vital part of botany as a 
science is, and must be, the study of process which creates and 
modifies structure as well as of process which is in its turn deter- 
mined by structure. In reality no line can be drawn between processes 
of these two kinds, for the development and metabolism of the plant 
form a continuous connected history in which process and structure 
continually act and interact. Nevertheless, the ‘ physiological func- 
tions’ of adult structures certainly have a special position in that the 
processes of which they consist are, like the adult structures themselves, 
the current terms of ontogenetic development, the current stages of 
full expression of the given genotype under the given conditions of life. 
The separation of morphology and physiology no doubt ultimately 
takes origin from the two distinct types of human interest in living 
organisms, characteristic of different types of mind, the one attracted by 
the forms, formal relationships and classification of objects, the other 
by the understanding of process, the knowledge of working. The one 
naturally observes and classifies, the other observes and experiments. 
This kind of separation, clearly enough seen among the older naturalists, 
has been greatly enhanced on the-one hand by the enthusiastic effort 
to trace phylogeny consequent on the acceptance of the doctrine of 
descent, on the other by the continuous complication of the physical 
and chemical knowledge and technique required by the study of physio- 
logical processes. It has had a profound effect on the teaching of 
botany during the past forty years. Botanists whose personal research 
lay in the one field have been less and less able to take an intelligent 
interest in the other, even’if they could understand the terms in which 
the results were expressed. The student has perforce come to regard 
and to study the two fields as wholly distinct, with very few points of 
contact, and hig attention has been directed primarily to morphology 
largely because it is so much easier for the beginner to examine and 
cut sections of plants and draw’ pictures of them than to study the 
processes which go to the making of them. Too little serious effort 
has been made to overcome the difficulties of teaching students to study 
process. The physiologists themselves have been too much absorbed 
in their apparatus to consider the bearing of their subject on general 
botany. In recent years the rise of new branches of study, such as 
cytology, genetics, and ecology, has added to the distraction of the 
student. 
The result has been to separate botany into disconnected parts and 
failure to give the student any unified notion of the subject. It is 
unnecessary to say that the growth of knowledge inevitably brings in 
ifs train ever-increasing specialisation in research, but that fact in no 
