200 
THOMPSON YATES LABORATORIES REPORT 
The Number of Altered Cells and their Positions in the Spinal Cord 
Owing to the same cells being seen in several consecutive sections, it was difficult to find a 
reliable method of enumeration. The numbers in the tables given were obtained as follows : — 
No normal cell was counted unless the nucleolus was clearly visible, and the same altered cell was 
of course not counted twice when it could be recognized as such. Another difficulty was that 
the affected cells are not uniformly distributed over the segment ; for example, thirty consecutive 
sections may show only normal cells, the next thirty a considerable number of affected ones. 
Hence for examination series of alternate tens of sections were taken. 
I Cat. Killed on the loth day. Section of Vlth, Vllth, Vlllth, IXth post-thoracic 
roots. 
Condition of postero-external group Condition of remaining cell groups 
Segment Total No. of No. of altered Total No. of altered cells in 
nucleoli counted cells Anterior group Median group 
VI o 
VII 247 55 23 
VIII 126 30 7 
2 Cat. Killed on I2th day. Section of Vlth, VII, Vlllth, IXth post-thoracic roots. 
VI o 
VII 187 44 5 
VIII 116 28 4 
3 Cat. Killed on 17th day. Section of Vlth, Vllth, Vlllth, IXth roots. 
VI 146 o 3 
VII 347 47 20 13 
VIII 86 28 
IX 112 9 4 
4 Cat. Killed on 23rd day. Section of Vth, Vlth, Vllth roots. 
V & VI o 
VII 73 33 
5 Cat. Killed on 2ist day. Section of Vlth, Vllth, Vlllth roots. 
VI 164 17 34 
VII 173 49 30 
VIII 70 9 10 2 
6 Cat. Killed on 24th day. Section of Vllth, Vlllth, IXth roots. 
VII 167 23 21 10 
VIII 119 8 4 2 
7 Monkey. Killed on 28th day. Section of Vth, Vlth, Vllth, Vlllth roots. 
V, VI & VIII a few 
VII Upper portion 55 27 1 4 2 
8 Cat. Killed on 17th day. Section of Vth, Vlth, Vllth, Vlllth cervical roots. 
V & VI o 
VII 112 13 14 
VIII a few 
9 Cat. Killed on 12th day. Vlth, Vllth, Vlllth cervical and 1st dorsal root. 
Practically no altered cells found. 
