2i6 THOMPSON YATES LABORATORIES REPORT 
shrunken and vacuolated, so that it was not possible to make any minute histological observations. No 
distinct diminution in number of the cells was noted on the side of the lesion. 
The anterior roots belonging to the segments whose afferent roots had been cut were stained in 
\ 7o osmic acid and teased. On examination it was found that about lo fibres of the Vllth anterior root 
showed marked Wallerian degeneration. 
In the Vlllth anterior root three degenerated fibres were counted. None were found in the Vth 
or Vlth segment. 
Exp. 2. Cat. Lived z^z days. Vth, Vlth, Vllth., Vlllth, and 1 Xth posterior post-thoracic roots cut. 
The animal showed the usual s)-mptoms, viz., it hopped about on three legs and did not use the 
foot of the limb on that side on which the roots had been cut. The foot on this side was ventro-flexed 
and motionless. The knee-jerk was absent. 
Vth segment. No altered cells found, and no degenerated fibres in the corresponding anterior root. 
Vlth segment. Series of 88 sections cut, of these half were examined and practically no altered 
cells found. 
Total number of nucleoli counted on side of lesion = 103. 
Total number of nucleoli counted on opposite side = 138. No degenerated fibres could be found 
in the corresponding anterior root. 
Vllth segment. Series of i8o sections cut and half examined, 23 cells found which showed 
evidence of chromatolysis. Their situation was as follows : posterior lateral group 16 ; anterior group 7. 
Total number of nucleoli counted on the side of lesion = 267. 
Total number of nucleoli counted on opposite side = 336. 
12 degenerated fibres were found in the corresponding anterior root. 
Vlllth segment. Series of i 50 sections cut, half examined, 6 altered cells found. 
Total number of nucleoli counted on side of lesion = 245. 
Total number of nucleoli counted on opposite side = 254. 
No degenerated fibre found in corresponding anterior root. 
IXth segment. No altered cells and no degenerated fibres. 
The microscopic examination showed that the diminution in ' number of nucleoli 
counted ' was due to a shrinkage and atrophy of the cells more than actual disappearance, and in 
some sections it could be seen that this slu-inkage was confined to the group of cells occupying 
the most lateral position of the horn. 
Many of the cells which showed chromatolysis were profoundly affected, being little more 
than mere shells. 
E'.xp. 3. Cat. Lived 74 days. Vth, Vlth, Vllth, and Vlllth posterior post-thoracic roots cut. 
Vth and Vlth segments. No distinct alteration. 
Vllth segment. Series of 90 sections cut, half examined, very few altered cells found. 
Total number of nucleoli counted on side of lesion = 134. 
Total number of nucleoli on opposite side = 145. 
Vlllth segment. Series of 100 sections cut, half examined. 20 altered cells found, situated as 
follows : posterior lateral group 19 ; median group i. 
Total number of nucleoli counted on side of lesion = 130. 
Total number of nucleoli counted on opposite side = 176. 
These observations show : — 
(1) That compared with the results obtained after similar procedure, but when the cord 
was examined at a much earlier date, the number of altered cells found is considerably less, i.e.., 
some have recovered. 
(2) That a considerable number of cells atrophy and shrink, and in some cases fibres 
presumably belonging to these cells undergo Wallerian degeneration. 
