136 SECTIONAL ADDRESSES. 
advance towards synthesis has accompanied it as new truths have been 
unfolded to the investigator. Here, as in other fields, the conception 
that the whole is the same as the sum of its parts is either meaningless, 
or, if it have any meaning, is untrue. Fresh reinforcements have 
steadily come to the idea that the animal body is not to be rightly con- 
sidered as a patchwork of the activities of its parts, but that the organism 
itself as a whole is the true physiological unit. In this conception the 
functions of the organs and of their own cellular subdivisions can only 
find due expression in relation to each other and to the functions of 
the whole. Just in proportion as analysis has proceeded with ever 
greater refinement to trace in terms of physics or chemistry the nature 
of given organic or cellular phenomena, the analysis itself is found to 
be pointing to new relationships between part and part of which the 
meaning is bound up in the unity of the organism. 
Of this continued absorption of analytic data into synthetic concep- 
tion, this interweaving of increasingly manifest diversities into an 
increasingly emergent unity, illustration can be found in many direc- 
tions. The name ‘hormone’ has been given to chemical products of 
particular organs which pass by way of the blood to stimulate another 
organ or other organs of the body to changes in activity. This mode 
of chemical regulation by messenger, so to speak, is superadded to the 
more rapid method of regulation by nervous impulse through the 
nervous system: and already many beautiful examples of delicate 
interplay and co-ordination have been discovered between the two kinds 
of regulation. In its earlier phases the knowledge of these messengers 
gave us a picture of relatively simple, though wonderfully adjusted, acts 
of chemical regulation. As analysis of the hormonic exchanges of other 
glands and tissues of the body has proceeded, however, a system of 
interplay and reciprocal function of increasing complexity has been 
revealed by later studies. Our knowledge of this is still young and 
quite rudimentary, but at every fresh step in this advance it becomes 
more evident that the multiplying facts can only be resumed by a con- 
ception of the whole organism as a unit of which the parts exist to 
preserve the integrity and ‘ normality.’ 
In the study of the nervous system, again, new methods of obser- 
vation and analysis have given us during the past half-century immense 
additions to our knowledge of the intricate fabrics of the brain and 
spinal cord and of the functions of the various systems of fibres and 
cells. The content of our knowledge of these must be tenfold that 
which was known fifty years ago. Here again, as investigation has 
gone forward, and as analysis has proceeded by methods so special and 
so refined that neurologists work, as it were, in a field of their own, it 
has proceeded only to reveal ever more and more clearly what Sherring- 
ton, one of the chief pioneers in this analysis, has himself called the 
‘integrative ’ action of the nervous system. The fabric of nerve cell 
and fibre, whether we trace its history from the lower to the higher 
animals, or whether we trace its complexity in the individual, is 
revealed to us as a series of superimposed controlling systems whose 
structural relations find intelligible expression only in terms of func- 
tions, and of functions of the animal as a whole. 
