52 O. LARSELL AND M. L. MASON 
broken up into the characteristic myelin droplets (fig. 2, my. dr.) 
of degenerated nerves. In the nerves from the other three 
animals (R8, R9, and R14) degeneration of the distal portion of 
the cut nerve was undoubtedly complete. 
Since the preparations were stained by the methylene-blue 
technique, the degeneration of fibers within the lungs themselves 
could only be inferred from the fact that a relatively very small 
number of fibers were stained in the main nerve trunks of the 
left lung. The corresponding nerve bundles of the right (normal) 
lung were very well stained in three of the animals, but very 
poorly in the fourth. The left lung of this animal (R14) gave 
Fig. 3 A cluster of four ganglion cells within the right lung of a rabbit (R7) 
whose left vagus had been sectioned and degenerated. The pericellular net- 
works about the cells have the normal appearance. Methylene-blue stain. 
60u. X 600. 
results comparable with those obtained from the corresponding 
lungs of rabbits R7, R8, and R9. The right lung of R14 was 
not well injected with the stain because of blocking of its pul- 
monary artery, so that a sufficient quantity of the stain did not 
have access to the proper regions of the lung to insure a good 
stain of the nerve fibers and terminations. 
Study of the intrapulmonary ganglia of the right lung in the 
three well-stained cases revealed an apparently normal picture. 
All or nearly all ‘of the cells were surrounded by more or less 
complete pericellular networks (fig. 3) which represent the termi- 
nations about these cells of preganglionic fibers from the vagus 
nerve. An occasional cell appeared destitute of such a network, 
