202 
THOMPSON YATES LABORATORIES REPORT 
persistence in some cells of the normal arrangement of the chromatic bodies, though these are 
much reduced in number and driven up to the periphery, the entire absence of vacuolation [see 
figures by Marinesco and others) and in many instances the maintained integrity of the cell 
processes. 
It may also be pointed out that the only artery divided in the operation is the posterior 
radicular, a small branch distributed to the caput and posterior root ; it does not extend much 
laterally and is in no relation with the large cornual cells, which are almost exclusively supplied 
by ramifications of the anterior spinal artery. 
The view I wish to maintain is that the changes are the result of the withdrawal of the 
afferent impulses which normally impinge upon the cornual cells. After sections of the posterior 
roots connected with a limb, the loss of muscular tone is pronounced, the limb is almost flail-like, 
and in addition to an ataxia. Dr. Mott and Professor Sherrington * have shown that there is a 
marked impairment of movement, especially of the hand or foot. Hence the anterior cornual cells 
must be in a highly altered functional state. 
The peculiar distribution of the altered cells affords further support in this view. 
First, as regards their marked limitation to the postero-external group. 
(1) Histological evidence shows that this group is most richly innervated by the collaterals 
from the posterior roots. 
In the cases of tabes dorsalis presenting muscular wasting, an affection of this group of cells 
has in several cases been found, and Charcot t attributed this to its intimate relation with the 
reflex collaterals. Schaffer J has also adopted this view and has described a case of tabes with 
atrophy of the peroneal muscles, in which certain cells of the anterior horn showed a chromatolysis. 
(2) The cells of the group also are connected with the muscles of the palm and sole, which 
are concerned in grasping movements of the hand and foot and opposition of the pollex ; 
movements wliich, as shown by Mor r and Sherrington, cannot be performed by an animal after 
the section of certain posterior roots. 
(3) The observations of the condition of the spinal cord in a large number of cases of old 
standing amputations uniformly show that the maximum in intensity of atrophy in the anterior 
cornual cells falls on the posterior external group. This fact led Friedlander and Krause§ to 
regard the group as sensory in nature and comparable with Clarke's column. 
HoMENjII in a detailed analysis of the condition of the spinal cord in the case of a Dog in 
which he had amputated the thigh 27 months previously, shows that the postero-external column 
was much more affected than any of the other remaining cell groups, and he also found a similar 
condition in amputation at the shoulder-joint. In such cases any alteration resulting in the cells 
from destruction of their axons must affect the several groups equally, and I shall show in the 
second part of this paper that division of an anterior root is followed by changes in practically all 
the cells on that side of the corresponding segment, and that these changes are not more advanced 
* Mott and Sherrington. ' Proc. Roy. Soc.,' 57, p. 481. 1895. 
\ Charcot. ' Lectures on Nervous Diseases.' 
j Schaffer. ' Revue Neurologiejue.' 1896. 
§ Friedlander u. Krause. ' Fortschritte der Medicin,' 
p. 749. 1886. 
II Homen. ' Ziegler's Beitr'age zur Path. Anat.' 1890. 
