40 
MR. C. S. SHERRINGTON ON OUT-LYING 
cornu, and sometimes reversely, the blunter end, devoid of any obvious cell process, 
is directed centrally, while the tapering extremity mingles with root-fibres on the 
distal side, and is turned away from the grey matter of the cornu. 
In rare instances is observable a deviation from the usual shape, which is less 
easy to reconcile with a belief that the cells are all of fairly regular bipolar form. 
Such an instance is represented in fig. 8, Plate 4. The impression is given of 
possession by the cell of two processes issuing from the cell-body in somewhat close 
juxtaposition, and both turned in a direction absolutely away from the grey matter 
of the dorsal horn. A little eminence rising from the ventrally-directed edge of the 
cell, is all that can suggest the giving off of a process toward the grey cornu. This 
very slight suggestion is ]:)erhaps strengthened by the fact that nerve-fibres (of the 
roots) in their centripetal path sweep by the little eminence in question, and the 
direction in which the eminence is set is certainly the same as theirs. As will have 
been gathered, the outlying cells strongly resemble in form the cells of Clarke’s 
column. This may be easily seen by a comparison of the two in one and the same 
section, especially in the lowest portions of the column, where, in Man, as pointed 
out by Mott,* * * § the arrangement of the component cells so as to have their longer 
axes parallel to the long axis of the cord is not so marked as is the case higher up. 
There, where cells of Clarke’s column may thus be viewed lengthwise in the same 
transverse section as contains the out-lying cells, the similarity in shape between them 
is too obvious to be overlooked. 
There is also a correspondence between the two in size. Measurements made of 
ten of the out-lying cells, taken at random, gave them an average dimension of 68’7 /x. 
This is larger than the average diameter assigned by some authorities (Gerlach, 
HenleI) to cells of Clarke’s column, but agrees fairly with the measurements given 
by Schwalbe I and Mott and the average size obtained by measurements of ten 
cells of Clarke’s column from the same seciions as furnished the out-lying cells 
measured, is 73 /x. 1| The actual measurements run as follows :— 
* ‘ Journ. of Anat. and Physiol.,' 1888. “ Microsc. Exam, of Clarke’s Column in Man, the Monkey, 
and the Dog,” by Fred. Mott, M.D., B.S. Lond., M.R.C.P., Lect. on Physiol, and Med. Regist., Charing 
Cross HosjDital. 
f ‘ Handb. der Nervenlehre,’ 1879. 
t ‘ Lehrb. der Neurologic,’ 1881. 
§ ‘ Journ. of Anat. and Physiol.,’ 1888. 
II [Gaskell has recently (‘ Journ. of Physiol.,’ vol. 10, 1889, p. 157) referred to the cells of Clarke’s 
column as “divisible into two groups, of different-sized cells,” and on that ground exception might be 
taken to the method of measurements for comparison employed above. I must confess, however, I have 
not been able to convince myself of the division of the cells into two groups, nor do I interpret the 
observations of Mott (‘Journ. of Anat. and Physiol.,’ loc. cit.) to be insripportof the division of the cells 
into two groups.—June, 1890.] 
