38 
MR. C. S. SHERRINGTON ON OUT-LYING 
the frontally directed cells in the reticularis may be considered to belong to part of 
the same system as do they. 
Besides the smaller nerve cells in the processus reticularis are some much larger, 
indeed, quite to be reckoned among the large ganglion cells of the cord. These are 
multipolar, and never, so far as I have seen, of bipolar form. They may measure 50 p, 
across, but it is the size of the cell-processes rather than of the cell-body, which is 
characteristic. On this account tliey contrast more strikingly with such cells as 
compose, for instance, the posterior vesicular column of Clarke, than do even the 
multipolar cells of the ventral cornu. Lying well out in the reticularis the appearance 
they olfer invites the idea that in them may be provided a nodal junction for the 
fibres that are there arriving along various planes. But it is difficult to adduce 
evidence for such a view. Schieeferdecker,'^^ who has furnished what appears to be 
the only definite reference to the cells of the processus reticularis, considers the cells 
typical representatives of his “ conducting ganglion-cells ” (Leiter-zellen) as dis¬ 
tinguished from “reflex ganglion-cells” (Beflex-zellen), the latter being such, for 
instance, as the multipolar cells grouped in the ventral grey horn. He does not 
advert to the existence of any large multipolar cells in the reticularis, and although 
the smaller spindle-shaped and triangular elements would obviously agree with the 
characters he describes for his “ conducting-cells,” it is not so obvious that he could 
attach the same meaning to the large-sized multipolar individuals -that one not rarely 
finds. Examples of these a]3pear, however, in the reticularis of all regions of the cord. 
Where the beams of the processus reticularis are thrust backwards towards the 
dorsal angle of the lateral column, and enclose a finer meshwork than they do more 
ventrally, ganglion-cells elongated in the direction of the length of the beams exist 
within them. Many are fusiform, and occur near or on bundles of medullated fibres 
which sweep laterally round the caput cornu dorsalis toward the base of the cornu. 
In the sacral cord, of the Monkey and Dog at least, nerve-cells are to be found lying 
considerably distant from the caput cornu within the dorsal part of the lateral white 
column, as represented in fig. 5, Plate 4. The arrangement of these tends to show a 
curvilinear grouping parallel with the outer edge of the lateral limb of the substantia 
gelatiuosa. Those that are within the strands continuous with the processes of the 
reticularis may, it would seem reasonable to conjecture, be connected with medullated 
nerve-fibres from the dorsal spinal nerve-roots, which curve round the dorsal horn on 
its lateral side. The individuals lying further outfit is difficult to suggest connections 
for. Their extension in the transverse plane of the cord must, one would think, mean 
that they communicate mainly with fibres that are taking a horizontal course in the 
lateral column at their level, but there is no evidence of more than sparsely scattered 
horizontal fibres in the neighbourhood. 
* ViRCirow’s ‘ Avcliiv,’ loc . cit . 
