PROCEEDINGS OF SOCIETIES. 95 
several papers, that no true termination or commencement has yet 
been demonstrated in the case of any nerve, seems to me to favour 
the conclusion that the action of a nervous apparatus results from 
varying intensities of continuous currents which are coustantly 
passing along the nerves during life, rather than from the sudden 
interruption or completion of nerve-currents. So far from any 
arrangement having been demonstrated in connection with any 
nervous structure which would permit the sudden interruption 
and completion of a current, anatomical observation demonstrates 
the structural continuity of all nerve-fibres with nerve-cells, and, 
indirectly through these cells, with one another. 
Fig. 5. 
Diagram to show possible relation of fibres from caudate nerve-cells, and 
fibres from cells in ganglia, as, for example, the ganglia on the posterior 
roots. a is supposed to be the periphery; the cell above 4 one of those in 
the ganglion. The three caudate cells resemble those in the grey matter of 
the cord, medula oblongata, and brain. 
I venture to conclude that the typical anatomical arrangement 
of a nervous mechanism is not a cord with two ends—a point of 
origin and a terminal extremity, but a cord without an end—a con- 
tinuous circuit. 
The peculiar structure of the caudate nerve-cells, which I have 
described, renders it, I think, very improbable that these cells are 
sources of nervous power, while, on the other hand, the structure, 
mode of growth, and indeed the whole life-history of the rounded 
ganglion-cells, render it very probable that they perform such an 
office. These two distinct classes of nerve-cells, in connexion with 
