10 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 
Cotylorhyza, etc.* In these forms Romanes sometimes obtained 
complete paralysis after the removal of the sensory clubs only, as also 
after the removal of the whole margin, though this was not marked 
in Aurelia. In Cyanza and other forms motor centers seemed to 
be more abundant than in Aurelia, so that paralysis was oftener 
followed by recovery. He concludes that while the principal motor 
centers reside in the lithocysts, other centers doubtless exist that 
may function vicariously, but that the centers of the margin are 
more definitely limited to the marginal bodies in the Scyphomedusze 
than in the Hydromeduse, in which the whole margin seems to be 
replete with centers. He feels positive, furthermore, that no motor 
centers exist in Aurelia’s margin outside of the marginal bodies 
(lithocysts). Eimer’s results are essentially the same as Romanes’, 
so that for a more detailed comparison of the two, Romanes’ works 
should be consulted. 
Romanes’ conclusion for the Hydromeduse is that the motor 
centers are not so definitely localized in the marginal bodies, but 
in the margin generally, the excision of the marginal bodies alone 
producing only partial paralysis, as would also the removal of the 
margin from between the marginal bodies, but not so marked. 
For the Hydromeduse he concludes, then, that all the centers of 
spontaneity are definitely localized in the margin, but not limited 
to the marginal bodies. To this he mentions one exception, namely, 
Staurophora laciniata, in which another center is found near the 
margin and two others in two opposite arms of the proboscis. 
I made the remark in an abstract (VI) on Conant’s notes that 
Romanes did not obtain recovery of pulsation after removal of all 
the lithocysts in Aurelia. As noted above, he did obtain recovery, so 
that Conant’s results on Charybdea and also Aurelia (see Polyclonia 
and Aurelia) are quite in agreement with Romanes. 
The paralysis following the removal of the clubs in Charybdea is 
evidently, primarily, the result of a loss of a part of its nervous 
mechanism (motor centers), and, secondarily, of nervous shock, and 
points to the existence of a definite nervous mechanism in the 
clubs. The histological evidence is here, as usual, corroborative of the 
physiological. 
Another interesting phenomenon observed after the removal of 
* Himer’s results I get from Romanes and Hesse". 
