16 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 
here be remembered that the interradial ganglia were probably 
removed at the removing of the margin.) 
Cutting the nerve in the eight adradii caused the pedalia to bend 
inwards at right angles to their normal position but did not in the 
least affect the coordination of the sides. When, however, the sides 
were cut in the eight adradii to the base of the stomach, coordina- 
tion for the main part ceased, and each side pulsated in its own 
rhythm. 
I have said that the principal centers of spontaneity reside in the 
radial ganglia. Upon further thought this hardly seems warranted. 
No doubt, among the principal motor centers must be placed the 
ganglionic masses of the clubs, and the radial ganglia, together 
with the homologous interradial ganglia, represent centers of equal 
value. I speak of these two sets of ganglia as homologous, since 
strictly speaking, they both belong to the margin, and the clubs at 
whose bases they lie probably represent modified tentacles. Conant’s 
experiments leave us in the dark as to the function of these ganglia. 
Next in order, it would seem, are the ganglion cells in the suspensoria, 
as is suggested by the contractions of an isolated side with a portion 
of a suspensorium attached. (See previous head.) While we have 
seen that the frenula and the velarium can contract by them- 
selves, yet, I find no evidence that these can impart their con- 
tractions to any adjacent tissue. 
Conant’s results on cutting the nerve eight times and then 
continuing the cuts to the base of the stomach are quite the same as 
Romanes and Eimer obtained upon Aurelia. Romanes, however, 
concludes that in his Sarsia, Tiaropsis, etc., coordination was broken 
when only short incisions were made in the margin. Charybdea 
appears, then, to agree with Aurelia rather than with the Hydrome- 
dus. Yet, since Romanes at first obtained similar results to those 
of Charybdea on Sarsia, but on further experimenting concluded that 
coordination had really been destroyed at the first cutting, we cannot 
speak with certainty that codrdination had not been destroyed in 
Charybdea before the cuts had been continued to the base of the 
stomach. I say not with certainty, because the injury to the bell 
being slight, coordination may have been maintained on the principle 
of a simultaneously (simultaneous for the octants) alternate exhaustion 
and recovery of the contractile tissue on the principle of Romanes’ 
theory. 
