514 O. LARSELL AND M. L. MASON 
of the cells of the intrapulmonary ganglia. The possibility that 
some of these fibers may come through the sympathetic from the 
upper white rami is not excluded. 
The nerve fibers in the smooth musculature of the bronchial 
tree, so far as could be determined, were stained in apparently 
equal numbers in both lungs and with equal intensity. This 
would appear to indicate that these fibers are all postganglionic, 
although it does not follow that all have their origin from intra- 
pulmonary cells. SSome may be axonic processes from cells of the 
ganglionic clusters in the posterior pulmonary plexus or else- 
where. Chase and Ranson (’14) state that the bronchial rami 
Fig. 5 Ganglion cells and nerve fibers from left lung of same animal (R7). 
No pericellular networks are present in this cluster of cells, although fine nerve 
fibers, believed to be postganglionic, are stained in the immediate vicinity of 
the cells. A single large fiber (s.fi.), probably sensory, is also present. Methy- 
lene-blue stain. 60u. X 600. 
of the vagus contain large numbers of myelinated fibers and 
take from the vagus nerve a considerable proportion of the 
myelinated fibers which have continued down to this level. 
Some of these are of large size and are undoubtedly sensory, but 
the majority are small and probably represent the preganglionic 
fibers to the lungs within the vagus nerve. The absence of any 
obvious degeneration of the nerve fibers to the bronchial muscu- 
lature speaks against Mollgaard’s statement that the bronchio- 
dilatator fibers take their origin from cells of the vagus ganglia. 
The number of stained nerve processes in the walls of the pul- 
monary blood-vessels also appears to be undiminished on the 
