406 PROCEEDINGS OF SECTION D. 
cells, in which, or through which, the mechanical or chemical 
process had to operate ; and that these same insignificant living 
units might have something to say in the transaction. 
Some separation was, to a certain extent, unavoidable. As the 
science of biology grew so rapidly, no one individual was capable 
of appreciating the details of all branches of the science, much less 
of being an investigator in many branches. Together with every- 
body else, students of biology had naturally to submit to differen- 
tiation of function. But I do not think that such a wide separa- 
tion, such that—metaphorically—morphologists and physiologists 
have hardly been upon speaking terms for many years, was 
necessitated by the exigencies of accumulated knowledge. 
THE CAUSES OF THE SEPARATION OF THE STUDIES OF 
STRUCTURE AND FUNCTION. 
I think it must be admitted that this separation occurred, firstly, 
owing to physiologists approaching the studies of the activities of 
living organisms from a point of view with which the anatomists 
were totally unsympathetic ; and secondly, in a minor degree, 
owing to the rapid development of the study of physiology along 
chemical and physical lines, which necessitated on the part of 
physiological investigators a previous considerable acquaintance 
with, and command of, physical methods of research. 
It was physiology that changed, not anatomy, or rather perhaps 
developed rapidly in the direction I have mentioned at this time, 
1845-50. Comparative anatomy continued, for the time-being, 
very steadily along the lines on which St. Hilaire and Miller had 
worked, the leading principle of which was homology. 
In reviewing the history of biological inquiry of the earlier part 
of this century, the most striking feature was the discovery, by 
Schwann, that the bodies of animals, just as had been shown to 
be the case with plants, were composed of cells. 
Schwann published his epoch-making results in his ‘ Micro- 
scopical Researches” in 1839. The ‘ Microscopical Researches ” 
contains, in addition to his work regarding cell structure, a 
deliberate attempt to explain cell formation and cell activities, as 
due to the molecular properties of the cell. According to this 
theory all physiological phenomena are either grossly mechanical, 
or to be explained by the chemical reaction of molecules. He 
was fully aware of the impossibility of presenting any sort of clear 
conception of the essential mechanism of vital phenomena, but 
insists most strongly that the consideration of physiological activi- 
ties from the point of view of chemistry and physics is likely to be 
more productive than their arrangement in a teleological category, 
as adopted for a definite purpose. 
