220 THOMPSON YATES LABORATORIES REPORT 
In his preliminary notes* Schafer gives the following conclusions. 
(1) The fibres of the pyramidal tract end in the grey matter at the base of the posterior 
horn and in Clarke's Column, but not in the anterior horn. 
(2) The fibres of the descending anterior lateral tract pass to the anterior horn and arborize 
around tlie anterior cornual cells. 
V. EFFECT ON THE CELLS IN THE ANTERIOR HORNS AFTER BOTH 
HEMISECTION AND DIVISION OF AFFERENT ROOTS ON THAT SIDE 
By such procedure the cells would be functionally isolated, and I have performed two 
experiments in order to see how far their anatomical integrity is preserved. 
Exp. I. Cat. Killed on I'^th day. Nearly complete he mi section in the mid-thoracic region and section of 
Fth, Vlth, Filth post-thoracic posterior roots. 
Vth segment. 86 sections cut, half examined. On the side of the lesion 6 cells showed chroma- 
tolysis, all situated in the posterior lateral group. No altered cells on the opposite side. 
Vlth segment. 56 sections cut, half examined. On the side of the lesion no altered cells found. 
On the opposite side three cells showed chromatolysis. 
Vllth segment. i6o sections cut, half examined. On the side of the lesion 20 cells showed 
chromatolysis all situated in the posterior lateral group. No altered cells on the opposite side. 
Exp. 2. Cat. Killed on the i ^th da'^. Nearly complete hemisection in mid-thoracic region and Vlth, Vllth, 
Vlllth, IXth posterior post-thoracic roots divided. 
Fig. 4 
Fig. 4. Diagram indicating position of altered cells after complete hemisection in mid-thoracic region and section 
of the posterior roots in the lumbo-sacral region. Sketch taken from Vlltli post-thoracic segment. Black circles indicate cells 
showing chromatolysis. Unshaded triangles normal cells. 
Side of Lesion. 
No. of sections 
Segment Post lat. Ant. lat. Central examined 
VI. No altered cells found. 55 
VII. 27 20 4+ 
VIII. 25 18 22 66 
IX. No altered cells found. 
(See Fig. 4.) 
* Schafer. 'Journal,' ' Proc. Physiol. Soc.,' March iSth and May 13th, 1899. 
