402 SYDNEY E. JOHNSON 
U 
a 2 
eae & A SPIRALS AND | SPIRALS AND 
a8 DATE OF °Z2]| srarnina | NETWORKS IN | NETWORKS IN ies 
S a OPERATION a 9 | METHOD ANTERIOR POSTERIOR 
Re Aa a GANGLIA GANGLIA 
Third lot—Continued 
11-13] Sept. 26,1917 36) Meth.-bl.| Several None 
14-27) Oct. 5, 1917 31; Meth.-bl.| Several None | Right trunk only 
of Spec. 27 
28-29! Oct. 5, 1917 31) Meth.-bl. Several | Several in| Dissection 
right showed that 
trunk,| right trunk 
none in had not been 
: left | severed 
30-36} Oct. 9, 1917 27| Meth.-bl. Several None 
27| Oct. 5, 1917 31| Pyri.-sil. Several None _ Left trunk only 
37| Oct. 5, 1917 21; Meth.-bl.| Like lots 1 Both trunks 
and) 2 missed in op- 
above | eration 
Destruction of the spinal cord alone (as far cephalad as the 
second or third vertebral segment) does not cause degeneration 
of all spiral and pericellular endings in the ganglia of the sym- 
pathetic trunks, but rather a progressive dropping out of these 
elements from the anterior to the posterior ganglia, a large 
number of networks appearing in the former and very few or none 
in the posterior ganglia. 
When all possible routes of entrance of preganglionic fibers to 
the sympathetic trunks have been eliminated and sufficient time 
allowed for degeneration, there is complete dropping out of all 
spiral fibers and pericellular networks. <A few spirals were found 
in specimen | (p. 397). These, I think, can be properiy ac- 
counted for on the basis of incomplete degeneration, as there 
was only the one instance out of a large number of specimens. 
Nerve endings of a different origin, if present, should be readily 
discovered in those preparations which are well stained and in 
which all preganglionic endings have been eliminated by degen- 
eration. Such endings have not been found. 
The observations presented above appear to me to show con- 
clusively, 1) that all of the nerve fibers which end in spirals and 
