SECTION OF NAKED-EYED MEDUS&. I1l5 
margin irritated as before, the manubrium would 
be able to localize better than if, as before, the 
radial distance between A B and ¢, d, e, f were less. 
The greater this radial distance, the better would 
be the localizing power of the manubrium; so that, 
for instance, if the cut A’ B’ were situated nearly 
at the base of the manubrium, the latter organ 
might be able to localize correctly a stimulus ap- 
plied, not only as before at f, but also at e ord. In 
such comparative experiments, however, it is to be 
understood that the higher up in the bell a cut is 
placed, the shorter it must be ; for a fair comparison 
requires that the two ends of the cut shall always 
touch the same two radii of the nectocalyx. Still, 
if the cut is only a very short one (say one or two 
millims. long), this consideration need not practically 
be taken into account; for such a cut, if situated 
just above the margin, as represented at a, will 
have the effect of destroying the localizing power of 
the manubrium as regards the corresponding are of 
the margin; but if situated high up in the bell, 
even though its length be still the same, it will not 
have this effect. 
From all this, then, we have seen that the con- 
nections which render possible the accurate localiz- 
ing functions of the manubrium are almost, though 
not quite, exclusively radial. We have also seen 
that between accurate localization and mere random 
movements on the part of the manubrium there are 
numerous gradations, the degree of decline from 
one to the other depending on the topographical 
relations between the point of stimulation and the 
