AUTHOR’S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, MAY ll 
AN INTRODUCTION TO A SERIES OF STUDIES ON THE 
SYMPATHETIC NERVOUS SYSTEM 
S. W. RANSON 
From the Northwestern University Medical School! 
ONE FIGURE 
Anatomists have devoted little thought to the functional 
pathways within the sympathetic nervous system. Yet it is 
obvious that no account of the structure of any part of the 
nervous system is complete which does not include an analysis 
of the more important conduction paths. Such an analysis 
cannot, as a rule, be made by purely morphological methods, but 
requires the aid of physiological procedures including degenera- 
tion experiments. Above all, the investigator must approach 
his subject from the right point of view; he must regard the 
structures to be analyzed as parts of a functional mechanism 
and strive to understand how it works. 
While histologists have given us many details concerning the 
structure of the ganglia, they have ignored the composition of the 
various nerves and plexuses in the sympathetic system and have 
made little effort to analyze what seemed to them a hopeless con- 
fusion of interconnected elements. In the anatomical and 
histological texts we find no hint that the sympathetic nervous 
system is made up of definite functional groups and chains of 
neurones as distinct and sharply limited as are any of the con- 
duction systems of the brain and spinal cord. Nevertheless, 
such is the case; it is even probable that the functional groups 
and chains of neurones are more sharply limited in the sympa- 
thetic than in the central nervous system. The latter is provided 
with a mechanism for the widest possible diffusion of incoming 
impulses, while such diffusion does not occur in the former. 
Strong stimulation of a single small cutaneous nerve will give 
1 Contribution No. 53, February 15, 1918. 
305 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 29, No. 4 
AuGustT, 1918 
