STRUCTURAL ALTERATIONS IN NERVE CELLS 
213 
IL EFFECT ON THE CELLS OF THE CORD AFTER SECTION OF 
BOTH ANTERIOR AND POSTERIOR ROOTS 
A single experiment was made with this object ; the Vth, Vlth, and Vllth roots on the 
left side were divided. The animal was killed on the lOth day. 
All the larger cells on the side of the lesion showed changes. The majority were only 
comparatively slightly affected to the extent seen after section of an anterior root alone ; others, 
however, showed a much more marked cliromatolysis, the change resembling that found after 
section of the afferent roots. 
In the Vth segment tlie anterior group was thus specially picked out, and in the Vlth and 
Vlltli the postero-lateral (Figs, i and 2). 
This group is thus again brought into prominence on account of the ease with which its 
cells undergo chromatolysis, and the experiment affords further explanation of the results obtained 
in old standing amputations, where of course both afferent and efferent fibres are cut and yet the 
ultimate damage in the cord is nearly limited to tliis region of cells. 
Fic. I 
Figs. I and 2. Diagrams illustrating the position of the altered cells found after section of both 
roots. Black circles indicate cells showing marked chromatolysis. Unshaded triangles indicate cells 
showing less change. Roots cut on left side only. Fig. 1 is from the Vth post-thonacic segment. Fig. z 
is from the Vllth post-thoracic segment. 
