26 PRESIDENT’S ADDRESS. 
tions, which reach their culmination in the workings of the human 
intellect. ‘ What a piece of work is a man! How noble in reason! 
How infinite in faculty! In form and moving how express and admir- 
able! In action how like an angel! In apprehension how like a god! ’ 
But lest he be elated with his psychical achievements, let him remem- 
ber that they are but the result of the acquisition by a few cells in a 
remote ancestor of a slightly greater tendency to react to an external 
stimulus, so that these cells were brought into closer touch with the outer 
world; while on the other hand, by extending beyond the circumscribed 
area to which their neighbours remained restricted, they gradually 
acquired a dominating influence over the rest. These dominating cells 
became nerve-cells; and now not only furnish the means for trans- 
mission of impressions from one part of the organism to another, but 
in the progress of time have become the seat of perception and con- 
scious sensation, of the formation and association of ideas, of memory, 
volition, and all the manifestations of the mind! 
The most conspicuous part played by the nervous system in the 
phenomena of life is that which produces and regulates the general 
movements of the body—movements brought about by 
Regulation of the so-called voluntary muscles. These movements are 
movements . : : 
by the ner- actually the result of impressions imparted to sensory 
vous system. or afferent nerves at the periphery—e.g., in the skin or 
Ei: in the several organs of special sense; the effect of these 
impressions may not be immediate, but can be stored for 
an indefinite time in certain cells of the nervous ‘system. The regu- 
lation of movements—whether they occur instantly after reception of 
the peripheral impression or result after a certain lapse of time; whether 
they are accompanied by conscious sensation or are of a purely reflex 
and unconscious character—is an intricate process, and the conditions 
of their co-ordination are of a complex nature involving not merely the 
causation of contraction of certain muscles, but also the prevention of 
contraction of others. For our present knowledge of these conditions 
we are largely indebted to the researches of Professor Sherrington. 
A less conspicuous but no less important part played by the nervous 
system is that by which the contractions of involuntary muscles are 
regulated. Under normal circumstances these are always 
+ aaapad independent of consciousness, but their regulation is 
brought about in much the same way as is that of the 
contractions of voluntary muscles—viz., as the result of impressions 
received at the periphery. These are transmitted by afferent fibres to 
the central nervous system, and from the latter other impulses are sent 
down, mostly along the nerves of the sympathetic or autonomic system 
of nerves, which either stimulate or prevent contraction of the involun- 
