SECTION OF COVERED-EYED MEDUS, 79 
appeared ; for just as in a piece of muslin the con- 
stituent threads, although trequently meeting one 
another, never actually coalesce, so in the nervous 
network of Aurelia, the constituent fibres, although 
frequently in contact, never actually unite. 
Now, if it is a remarkable fact that in a fully 
differentiated nervous network the constituent 
fibres are not improbably capable of vicarious action 
to almost any extent, much more remarkable does 
this fact become when we find that no two of these 
constituent nerve-fibres are histologically continuous 
with one another. Indeed, it seems to me we have 
here a fact as startling as it is novel. There can 
scarcely be any doubt that some influence is com- 
municated from a stimulated fibre a to the adjacent 
fibre b at the point where these fibres come into close 
apposition. But what the nature of the process 
may be whereby a disturbance in the excitable 
protoplasm of a sets up a sympathetic disturbance 
in the anatomically separate protoplasm of 8, 
supposing it to be really such—this is a question 
concerning which it would as yet be premature 
to speculate. But I think it may be well for 
physiologists to keep awake to the fact that a 
process of this kind probably takes place in the 
ease of these nerve-fibres. For it thus becomes a 
possibility which ought not to be overlooked, that 
in the fibres of the spinal cord, and in ganglia 
generally, where bistologists have hitherto been un- 
able to trace any anatomical or structural continuity 
between cells and fibres, which must nevertheless 
be supposed to possess physiological or functional 
