COMMISSURAL NEURONES 401 
i 
Ps 
Als fa SPIRALS AND | SPIRALS AND 
32 DATE OF 04%] sTainiIna | NETWORKSIN | NETWORKS IN ae ee 
og OPERATION 209] METHOD ANTERIOR POSTERIOR 
By % = Ae GANGLIA GANGLIA 
First lot, 72 frogs, received March 20, 1917—42 operated (spinal cords destroyed); 
84 survived operation 
1} Mar. 29,.1917 9} Meth.-bl.| Many Many Normal _histo- 
logical picture 
2) Mar. 29, 1917 9| Pyri.-sil. Many Few Evident signs of 
degeneration 
in the most 
posterior 
ganglia 
Meth.-bl.| Many Several Signs of degen- 
eration in the 
posterior 
ganglia 
4| Apr. 5 , 1917 46} Meth.-bl.| Many Few Degeneration 
more evident 
in posterior 
ganglia 
5) Apr. 5, 1917 56} Meth.-bl.| ~ Many Few Marked degen- 
eration in pos- 
terior ganglia 
6) Apr. 5, 1917 56| Pyri.-sil. Several Very few | As above 
7-10) Apr. 21, 1917 53] Pyri.-sil. Several Very few | As above 
11-19} Apr. 21, 1917 |48-54| Meth.-bl.| Several Very few | As above 
3} Mar. 29, 1917 
bo 
(2) 
Second lot, 72 frogs, received June 7, 1917—54 operated as described above, all 
dying but one during my summer absence of three months 
1-54| June 7-14 loz or| 1 frog, Several Few | Marked drop- 
more| Meth.-bl. ping out of 
| spirals in pos- 
| terior ganglia 
Third lot, 72 frogs, received Sept. 21, 1917—52 operated (spinal cords destroyed and 
and both sympathetic trunks severed unless otherwise noted ); 37 survived 
operation 
1-10} Sept. 26, 1917 |27-29| Meth.-bl.| Several | A few in| Essentially a 
! specimen, complete drop- 
1 only ping out of 
spirals and 
networks in 
ganglia poste- 
rior to section 
of sympathetic 
trunks 
THE JOURNAL OF COMPARATIVE NEUROLOGY; VOL. 29, No. 4 
