OCTOBER 8, 1897. ] 
inductive method of research as now laid 
down the comparative method, and extend- 
ing his researches down into the Pterido- 
phyta and Bryophyta, he not only estab- 
lished for these groups facts in sexuality 
which Camerarius and Robert Brown had 
done for the Spermatophyta, but he did it 
in a far superior manner. He thus laid the 
foundation for our present conceptions of 
the comparative morphology of plants. 
Naegeli’s investigations of the cell had em- 
phasized the importance of its study in de- 
velopment and now the relation of cell 
growth to the form of plant members was 
carried to a high degree, and an attempt 
was made to show how dependent the form 
of the plant was on the growth of the apical 
cell in the Pteridophyta and Bryophyta, 
though later researches have modified this 
view, and how necessary a knowledge of the 
sequence of cell division was to an under- 
standing of homologies and relationships. 
Thus in developmental and comparative 
studies morphology has been placed on a 
broader and more natural basis, and the 
homologies and relationships of organs be- 
tween the lower and higher plants are better 
understood. 
But the growth of comparative mor- 
phology has been accompanied by the in- 
terpretation of structures usually from a 
teleological standpoint, and in many cases 
with the innate propensity of the mind to 
look at nature in the light of the old ideal- 
istic theories of metamorphosis. 
I wish now to enquire if we have not re- 
cently entered upon a new period in our 
study of comparative morphology. There 
are many important questions on which 
comparative studies of development under 
natural or normal conditions alone cannot 
afford a sufficient number of data. We are 
constantly confronted with the problems of 
the interpretation of structure and form, 
not only as to how it stands in relation to 
structures in other plants which we deal 
SCIENCE. 
539 
with in comparative morphology, but the 
meaning of the structure or form itself, and 
in relation to the other structures of the 
organism, in relation to the environment 
and in relation to the past. This must be 
met by an enquiry on our part as to why 
the structure or form is whatit is, and what 
are the conditions which influence it. This 
we are accustomed to do by experiment, and 
it begins to appear that our final judgments 
upon many questions of morphology, es- 
pecially those which relate to variation, 
homology, etec., must be formed after the 
evidence is obtained in this higher trial 
court, that of experimental morphology. While 
experimental morphology as a designation 
of one branch of research in plants, or as a 
distinct and important field of study, is not 
yet fully taken cognizance of by botanists, 
we have only to consult our recent liter- 
ature to find evidence that this great and 
little explored field has already been en- 
tered upon. 
Experimental methods of research in the 
study of plants have been in vogue for 
some time, but chiefly by plant physiolo- 
gists and largely from the standpoint of the 
physical and chemical activities of the 
plant, as well as those phases of nutrition 
and irritability, and of histologie struc- 
ture, which relate largely to the life pro- 
cesses of the plants, and in which the physi- 
ologist is therefore mainly interested. In 
recent years there has been a tendency in 
physiological research to limit the special 
scope of these investigations to those sub- 
jects of a physical and chemical nature. At 
the same time the study of the structure and 
behavior of protoplasm is coming to be re- 
garded as a morphological one, and while 
experimental methods of research as applied 
to the morphology of protoplasm and the 
cell is comparatively new there is already 
a considerable literature on the subject, 
even from the side of plant organisms 
(Davenport, 797). While certain of the 
