436 S. W. RANSON AND P. R. BILLINGSLEY 
autonomic fibers and visceral afferent fibers. In the majority 
of the specimens studied (eight out of ten) it was not possible to 
demonstrate any group of fibers that could be identified as post- 
ganglionic. We shall see that these conclusions agree with those 
of Langley. The statements which appear in the citation below 
will be found scattered through several pages of text (Schiéfer’s 
Physiology, vol. 2, pp. 644, 646, 648): 
By dissection, it is easy to see that a large proportion of the splanchni¢ 
nerve fibers arise from the white rami communicantes, running in the 
sympathetic chain for a variable distance. In the cat and dog the fibers 
of the great splanchnic nerve can be traced upwards in the sympathetic 
chain as far as the sixth thoracic ganglion. And there is good reason 
to believe that all the splanchnic fibers are the direct continuation of the 
fibers of the white rami. It can easily be shown in the rabbit that the 
very great majority of the fibers running from the spinal cord to the 
abdominal viscera end in the prevertebral ganglia. After injection of a 
small amount of nicotine in the rabbit, the nerve roots, the splanchnies 
proper, and the inferior splanchnics have either no effect or a mere trace 
on the blood vessels or abdominal and pelvic viscera; but all the normal 
effects can be readily obtained by stimulating the fibers given off by the 
prevertelral ganglion. It has long been known that the major splanch- 
nic contains a considerable number of non-medullated fibers, and it is in 
large part this fact which has led to the unquestioned belief that the 
ganglia of the sympathetic chain send fibers to the solar ganglia or to 
the abdominal viscera. If, then, the view which I have given above be 
accepted, namely, that very few if any fibers pass from the cells of the 
vertebral ganglia to the splanchnic nerves, we must take the non- 
medullated fibers to be preganglionic fibers which have lost their medulla. 
According to Langley, the majority of the efferent fibers of 
the greater splanchnic terminate in the solar ganglion, though 
a few may pass on to more distal ganglia. He also admits the 
possibility that occasionally a few postganglionic fibers arising 
from cells in the ganglia of the trunk may run through the 
splanchnic to the coeliac plexus. The physiological experiments 
on which his conclusions are based are found in the papers by 
Langley and Dickinson (’89), Langley (’96 b), and Bunch (’97). 
It will be seen that our histological results are in agreement 
with those obtained by physiological experimentation. We have 
seen reason to believe that the unmyelinated fibers in the splanch- 
nic which Langley thought might be preganglionic fibers that had 
lost their sheaths, are instead afferent fibers. More convincing 
