112 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 
I shall now proceed to consider the nature of the 
nervous connections between the nectocalyx and 
manubrium of this Medusa. 
Bearing in mind that in an unmutilated Tiaropsis 
indicans the manubrium invariably localizes with 
the utmost precision any minute point of irrita- 
tion situated in the bell, the significance of the 
following facts is unmistakable, viz. that when a 
cut is introduced between the base of the manu- 
brium and the point of irritation in the bell, the 
localizing power of the former, as regards that point 
in the latter, is wholly destroyed. For instance, if 
such a cut as that represented at a (see Fig. 22) be 
made in the nectocalyx of this Medusa, the manu- 
brium will no longer be able to localize the seat of 
a stimulus applied below that cut, as, for instance, 
at b. Now, having tried this experiment a number 
of times, and having always obtained the same 
result, I conclude that the nervous connections be- 
tween the nectocalyx and the manubrium, which 
render possible the localizing action of the latter, 
are connections the functions of which are intensely 
specialized, and the distribution of which is radial. 
So far, then, we have highly satisfactory evidence 
of tissue-tracts performing the function of afferent 
nerves. But another point of interest here arises. 
Although, in the experiment just described, the 
case bending over in whatever direction it was needful for it to 
bend, in order to approach the seat of stimulation. This shows 
that the analogue of ganglionic function must here be situated in 
at least more than one part of a tentacle ; and I think it is not 
improbable that, if trials were expressly made, this function would 
be found to be diffused throughout the whole tentacle. 
