96 SYDNEY E. JOHNSON 
coccygeal region. As in other ganglia, the majority of the 
medullated fibers are located peripheral to the ganglion cells. 
The ganglion in this case is larger than usual and apparently 
receives the terminations of approximately 185 medullated 
preganglionic fibers. 
The second sacral internode consisted of three fine nerve 
strands with a total of 178 medullated fibers. Sixty-seven of 
these fibers run into a ramus a short distance caudad to the 
ganglion. 
The third sacral ganglion in this specimen was exceptionally 
small, producing only a slight enlargement in the diameter of 
the trunk. The ganglion was fused with its fellow of the opposite 
side and four nerve strands connected the united ganglionic 
mass with the first coccygeal pair of ganglia. These four nerve 
strands comprised the internodal segments of both trunks. 
Together they contained a total of 254 medullated fibers. This 
would allow an average of half that number for each internodal 
segment. 
The coccygeal trunks present the same general characters as 
the sacral. Sections were made to and including the third 
coceygeal internodal segment, and the outstanding feature in 
these specimens is the presence of a relatively large number of 
fibers (sensory) with diameters ranging from 5 to 9 or more 
micra. 
Results of the experiments 
As described in a previous section, the experimental material 
was obtained, 1) by dividing both sympathetic trunks between 
the seventh lumbar and the first sacral ganglion and allowing 
twenty-five to thirty days for degeneration to take place before 
removing the sacral trunk for staining and, 2) by dividing the 
trunks as stated above and in addition dividing or destroying 
the spinal nerve roots distal to the spinal ganglia. These animals 
were kept alive from twenty-five to thirty days from the time 
of the second operation. 
For the first series of experiments twelve cats were operated, 
one after another as time permitted over a period of almost two 
