392 SYDNEY E. JOHNSON 
tions the pyridine silver stain appeared to be more sensitive to 
degenerative processes than methylene blue. 
Twenty-eight days were allowed to elapse before the next 
specimens were injected with methylene blue. These showed a 
marked dropping out of pericellular baskets and spirals, especi- 
ally in the posterior ganglia. ‘ 
He 
Fig. 4 Autonomic cell of normal frog, stained by pyridine silver method. 
> be ® 
Fig. 5 Small section of a normal sympathetic ganglion stained by pyridine 
silver method. The preganglionic fibers are darkly stained and stand out in 
marked contrast to the neuraxes of the autonomic cells. X 1114. 
After thirty-three days the ganglia of four specimens were 
stained by the pyridine silver process, and all of these showed 
marked degeneration in the posterior ganglia. In these many 
spirals could be found in the anterior ganglia (fig. 8), and it is 
significant to note that the spirals present appeared to be as well 
stained as those of normal ganglia. This would appear to indi- 
cate that the cells of origin of these particular spiral fibers had 
not been destroyed by the operation. Thus these spirals could be 
