STRUCTURAL ALTERATIONS IN NERVE CELLS 201 
In addition to the cells of the anterior horn, the small cells present in the posterior horn 
showed in some instances a similar alteration. 
The condition of the opposite side is important ; in two cases it was entirely free from 
any altered cells ; in four others a few cells, the total number being under ten, were found which 
showed the characteristic chromatolysis. In the three other cases a larger number were found ; 
in two instances these were in the Vlth segment, in the anterior or median groups — they were 
present in greatest number in the Vllth segment, and here again at least half were found in the 
anterior cell group ; segments VIII and IX were practically free. 
Sl'MMARV OF THE RESULTS OF THESE EXPERIMENTS 
After section of several posterior roots, from the Vth to the IXth post-thoracic inclusive, a 
considerable percentage of obviously altered cells arc found, their distribution in the case of the 
cat is practically limited to the Vllth and Vllltii segments, and especially to the postero-lateral 
group of cells in those segments. 
In the Monkey the upper part of the Vllth segment is picked out. The effect is to a 
very slight extent a crossed one, and presents the remarkable feature that more affected cells were 
found in the Vlth segment of the crossed side than on the side of the lesion. 
In the cervical region, in one case similar but slight changes were found limited to the 
Vllth segment ; in the other case the spinal cord was practically normal. 
Significance of these Results 
An examination of a large number of sections from normal spinal cords failed to show cells 
in any way comparable to those just described, and the question of artefaction can, I think, be 
dismissed. 
Neither is the escape of the cerebro-spinal fluid capable of producing any such alteration. 
Sections cut above the seat of lesion, but from a piece of the cord over which the dura mater had 
been opened, always showed the typical normal structure. 
With regard to inflammation and disturbance of the blood supply, the great number of 
sections were entirely free from any sign of inflammation or connective tissue change, and except 
for the presence of the altered cells the side of lesion could not be recognized. I do not think 
that the connective tissue change is attended by any comparable alteration in the cornual cells. 
In some sections in which there was proliferation of the tissue of the posterior horn extending 
inwards in the grey matter, no alteration whatever was observed in the cells. If it produces any 
change, it is most likely one which causes shrinkage and disappearance of the cells, and 
not an alteration such as that described. That the nerve-cells undergo profound alteration in 
consequence of a disturbance in the vascular system is well known from the work of Munzer 
and Wiener,* MARiNEsco,t Lamy,J and Ballet.§ 
But certain appearances of the cells noted in my observations are not generally found as 
the result of a primary vascular disturbance : viz., the eccentric position of the nucleus ; the 
* Miinzer u. Wiener. 'Arch. f. exper. Path. ii. Pharm.' X Lnmy. ' Archives de Physiol, norm, et path.' p. 1 84. 1897. 
f Marinesco. La ' Presse Medicale.' Jan. 27, 1897. ^Ballet. Le ' Progres Meilical.' June 27, 1896. 
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