334 S. W. RANSON AND P. R. BILLINGSLEY 
supported. In regard to this point Huber (’13) has recently 
said 
the evidence presented by Cajal, Dogiel, Retzius, Huber, and others 
cannot be regarded as entirely conclusive, since it has not been de- 
termined that the fine medullated fibers or the unmedullated fibers 
which appear to enter the spinal ganglia from without and end in 
pericellular plexuses, are, in fact, the neuraxes of sympathetic neurones. 
Very strong evidence has been presented by Langley (’03) to 
show that no medullated sensory fibers run from the sympathetic 
to the spinal ganglia. 
As regards the white rami, which contain most of the afferent visceral 
fibers, there is conclusive evidence that the very great majority of 
them have their trophic center in the posterior root ganglia. It con- 
sists in the fact that after intraspinal section of a nerve just periph- 
erally of the posterior root ganglia, either all, or all but a few, of the 
medullated fibers in the white rami degenerate; and that after section 
of the sympathetic or of the splanchnic or of the inferior splanchnies 
no degenerated fibers are present in the white rami. 
Similarly in the sacral autonomic system, the pelvic nerves contain 
about 1,000 afferent nerve fibers, and about twice this number of 
efferent nerve fibers; on cutting the roots of the sacral nerve, as shown 
by Anderson and myself, about half a dozen fibers only remain unde- 
generated in the pelvic nerve, and these are probably post-ganglonic 
medullated fibers. 
Axons of the cells of the sympathetic ganglia. In pyridine silver 
preparations of the superior cervical ganglia of the cat, dog, and 
man, it is very difficult to follow an axon for any considerable 
distance. In fact, it is usually no easy matter to tell which of 
the several processes of a cell is to be regarded as an axon. In 
a preceding section of this paper it has been shown that some of 
these axons acquire a myelin sheath. According to Ko6lliker 
(96) and Langley (’00), these axons always end at the periphery, 
and never terminate in the sympathetic ganglia. 
According to Cajal (’11), who worked with the Golgi and meth- 
ylene blue stains on the sympathetic ganglia of animals and 
with his silver stain on the superior cervical ganglion of man, 
the axons of the cells of the sympathetic ganglia are rather thick, 
smooth, and devoid of branches. He says that his anatomical 
studies are in accord with the physiological experiments of Lang- 
