306 S. W. RANSON 
rise to nerve impulses which are distributed throughout the brain 
and spinal cord and may eall into action any part of the smooth 
or striated musculature of the body. Nothing in any way com- 
parable to this occurs in the sympathetic system. 
Excluding the terminal ganglionated plexuses which require 
further study, we may say that there is probably no more op- 
portunity for diffusion of nerve impulses in the sympathetic nerv- 
ous system than there is in an ordinary spinal nerve. This ean 
Fig. 1 Diagram of two conduction paths from which all purely topographic 
details, such as spinal nerves, rami communicantes, and sympathetic trunk, have 
been omitted: a, somatic path with branching efferent fiber; 6, autonomic path 
with branching preganglionic efferent fiber, the branches ending in relation to two 
postganglionic neurones. 
be made clear by a diagram (fig. 1). So far as the possibility 
for diffusion of nerve impulses is concerned, it is immaterial 
whether the efferent fiber branches in the course of a nerve or 
within a ganglion and whether its branches come in contact with 
the innervated structure directly or through the mediation of a 
second neurone, provided there is in the ganglion no other type 
of synapse than that indicated in the diagram. 
Thanks to the work of Langley, we have reason to believe that 
the sympathetic system, with the probable exception of the 
terminal ganglionated plexuses, is built up on the simple lines 
