356 S. W. RANSON AND P. R. BILLINGSLEY 
of one cell may form baskets or other special endings about 
neighboring cells, but these dendritic endings seem to be always 
outside the capsule of the second cell and therefore could not 
transmit impulses to it. 
Sensory neurones with long dendrites have been described in 
sympathetic ganglia by Dogiel, but a review of the literature on 
this point shows that his interpretation of these structures has 
received little support from the observations of others. It is also 
doubtful if the axons of cells in the sympathetic ganglia run to 
spinal ganglia to form baskets about the cells located there. 
The axons of sympathetic ganglion cells may acquire myelin 
sheaths, but usually do not. A study of the literature would 
indicate that they usually run, without giving off collaterals, 
into one of the branches of distribution arising from the ganglion. 
Some run through a connecting nerve to another ganglion, but 
there is no evidence to show that they ever end there. It would 
seem more likely that these fibers merely run through this second 
ganglion to join the nerve to which they are distributed. Some 
postganglionic fibers give off collaterals either in the original 
ganglion or in a second ganglion through which they pass, but 
these collaterals have been shown by Michailow to have endings 
not well adapted for the transference of nerve impulses. 
Between the cells is a rich plexus of fine axonic ramifications 
which is formed by the branching of the preganglionic fibers. 
This disappears when the preganglionic fibers degenerate. It is 
probable that many of the fibers of the intercellular plexus form 
synapses with the dendrites of the sympathetic ganglion cells. 
In pyridine silver preparations of the superior cervical ganglion 
of the cat it is possible to trace the darkly stained preganglionic 
fibers from the sympathetic trunk and to see that they undergo 
repeated branching and take a large part in the formation of the 
intercellular plexus. The postganglionic fibers, which are more 
lightly stained, and for the most part devoid of branches, take 
only a minor part in the formation of this plexus, but become 
grouped into bundles of parallel fibers which run toward the 
branches of distribution of the ganglion. 
There is no evidence for the existence of synapses, either com- 
missural or sensory-motor, between the neurones located in the 
