364 P. R. BILLINGSLEY AND S. W. RANSON 
The evidence is against the existence of any purely intragan- 
glionic or commissural neurones; and there is no evidence of the 
existence of any sensory neurones in this ganglion. No doubt 
the high ratio of fibers to cells will appear to some as an evi- 
dence of intraganglionic commissural neurones. But a careful 
reading of the paragraph from Gaskell quoted on page 360 should 
do away with any feeling that the ratio of preganglionic to post- 
ganglionic neurones here given is unreasonably high. 
To one who is familiar with the intricate feltwork produced 
by the fine branches of the preganglionic fibers which we have 
described under the name of intercellular plexus (p. 337) it does 
not seem unreasonable that one preganglionic fiber should form 
direet synaptic connections with thirty-two postganglionic neu- 
rones. However, we do not wish to urge this point and must 
admit that, although no satisfactory evidence of their existence 
has ever been presented and although we have very strong evi- 
dence against their presence in certain ganglia, it is nevertheless 
possible that there may be some intraganglionic commissural 
neurones in sympathetic ganglia. If there were any in the 
superior cervical ganglion the ratio here stated would be by that 
much reduced. With regard to the second question we cannot 
say with certainty to what extent the fibers ascending in the 
cervical sympathetic trunk may have given off collaterals in the 
middle cervical and stellate ganglia. We possess, however, in- 
formation which makes it possible to form an intelligent opinion 
on the question. 
The middle cervical ganglion is small and inconstant. The 
stellate ganglion, on the other hand, is large and contains many 
cells. All the preganglionic fibers running to the superior cer- 
vical ganglion must pass by or through it. To what extent do 
they give off collaterals to its cells? Some information on this 
subject may be gained by a study of the results obtained by 
Langley (’92) from stimulating the upper thoracic nerves of the 
cat within the spinal canal. So far as the fibers running to 
the superior cervical ganglion are concerned, he has shown that 
those for the dilation of the pupil arise from the first three thoracic 
nerves, those for the nictitating membrane, submaxillary sali- 
