1893.] Physiology and Morphology. 803 
phologists. ‘That we have to deal with functions of organisms 
as wellas with functions of organs, is a truth that could not 
escape the student of Darwin’s or Wallace’s works. Still we 
have just begun to heed the fact that the broader physiology 
of the future must include the biological economy of organ- 
isms as well as the functional economy of organs. I repeat 
the biological economy of organisms must become an integral 
part of physiology, not only in theory, but in practice as 
well. 
The activities and inter-relations of organisms bear the same 
relation to their morphology, as do the functions and correla- 
tions of organs to their anatomy. ^ The former activities differ 
from the latteronly in degree, just as an organism differs from 
an organ only asa composite differs from a simple. As the 
morphology of organisms includes organology, so the physiol- 
ogy of organisms embraces the functions of organs.  Asthe 
one covers all organic forms from the most minute and simple 
to the most highly differentiated and complex, so the 
other covers all vital phenomena, whether manifested in the 
smallest particle of living protoplasm, in a cell, a special tissue, 
an organ, an organism, a species, or any group of organisms. 
Form and function are always the two aspects, inseparably 
linked together throughout the entire organic world. 
The work of the physiologist runs perfectly parallel with 
that of the morphologist, and wherever the one divides there 
the other divides, and for precisely similar reasons. We have 
the morphology of adult individuals, likewise the physiology ; 
we have the morphology of the developing individual (onto- 
geny), likewise embryological physiology (“ physiontogeny ”) ; 
then we have the morphology of the species (phylogeny), and 
along side the physiology, or the phylogeny of functions 
(* physiophyly, ” Haeckel). 
Metaphysiosi$ is as old and as universal as metamorphosis, 
and to attempt to explain functions as we find them to-day 
without considering their historical development, is in many 
cases at least, as idle as trying to account for the specified forms 
word suggests itself so readily, that it will hardly be reco gnized as novel ; it is 
at least self-defining. 
