394 SYDNEY E. JOHNSON 
The posterior ganglia (i.e., the 8th, 9th, or 10th) of the same 
specimens showed evident signs of degeneration. In these 
there could be seen only an occasional spiral and _ pericellular 
basket and a relatively small number of preganglionic fibers. 
The neuraxes of the autonomic cells, although faintly stained, 
show more prominently as they are not obscured by the’ presence 
of the darkly stained preganglionic fibers (fig. 7). 
As the experiments described above were carried out on winter 
frogs, I was not sure that the time allowed had been sufficient 
Fig.8 Small section of an anterior ganglion stained by pyridine silver process 
thirty-three days after destruction of spinal cord. <A few spirals could be found 
in all the ganglia of the anterior portion of the sympathetic trunk. X 1144. 
for complete degeneration of the preganglionic fibers. In order 
to remove all doubt on this point, a second lot of frogs was oper- 
ated as indicated below. 
Second lot of frogs—spinal cords destroyed. ‘This lot of frogs 
was received on June 7, and fifty-four were operated in the same 
manner as described above. The operated frogs were put into a 
large tank and with them was included a small number of normal 
frogs for controls. Upon my return to the laboratory after an 
absence of three months, I found that all of the frogs had died 
