Regeneration in Rhizostoma Pulmo. 



11 



several contractions following each other in regular succession, 

 though never continuing beyond three or four pulsations. 



May 14th. — The medusa, while still more or less passive as 

 before, was yet apparently recovering more of the power of spon- 

 taneity, several pulsations occurring at more frequent intervals, 

 but these were not of sufficient vigor to produce any locomotion. 



--ai 



Fig. I. 



Diagram showing methods of excising rhopalia. 



a, usual triangular excision; ai, excision of larger mass; b, rectangular form 

 of excision; c, circular form of excision; d, form of rhopalium and lappetts. 



May 15th. — During this and the following day there was an 

 apparent relapse of the medusa to the condition of the first day. 

 There was also less vigor apparent, such stimuli as those referred 

 to above producing but slight effects. This condition continued 

 during the i8th, 19th and 20th. 



