SECTION. OF NAKED-EYED MEDUS&. 109 
‘crouching attitude in which this movement termi- 
nates continues for one or two seconds, after which 
the organ begins gradually to resume its former 
dimensions. Concurrently with these movements 
on the part of the manubrium, the portion of the 
nectocalyx which has been stimulated bends inwards 
as far as itis able. The manubrium now begins to 
deflect itself towards the bent-in portion of the 
nectocalyx ; and this deflection continuing with 
a somewhat rapid motion, the extremity of the 
manubrium is eventually brought, with unerring 
precision, to meet the in-bent portion of the necto- 
calyx. I here introduce a drawing of more than 
life-size to render a better idea of this pointing 
action by the manubrium to a seat of irritation 
located in the bell. It must further be stated that 
in the unmutilated animal such action is quite 
invariable, the tapered extremity of the manubrium 
never failing to be placed on the exact spot in the 
nectocalyx where the stimulation is being, or 
had previously been, applied. Moreover, if the 
experimenter irritates one point of the nectocalyx, 
with a needle or a fine pair of forceps. for instance, 
and while the manubrium is applied to that 
point he irritates another point, then the manu- 
brium will leave the first point and move over 
to the second. In this way the manubrium may be 
made to indicate successively any number of points 
of irritation; and it is interesting to observe that 
when, after such a series of irritations, the animal 
is left to itself, the manubrium will subsequently 
continue for a considerable time to visit first one 
6 
