7 8 Charles JV. Hargitt. 



May 2 1 St. — The medusa seemed to have recovered the vigor 

 or tone to which reference has been made above. There was 

 also a very evident rhythm in the contractions, often as many as 

 ten or more regularly recurring pulsations occurring at irregular 

 intervals during the day. As before, however, they were not of 

 sufficient force to secure the locomotion of the animal. The same 

 condition was observable during the following day. 



May 23d. — There was again a marked decline in both vigor 

 and general tone of the body, which showed evident signs of de- 

 generation. This condition continued during the following day, 

 and on the morning of the 25th the medusa was found to have 

 died during the preceding night. 



Upon careful examination it was found that wherever tissue 

 had been mutilated or excised there had been a definite healing 

 of the wounds and in the case of the oral arms there were indica- 

 tions of new growth. I was not able to distinguish that there had 

 been any regeneration of the sensory organs, and this will appear 

 somewhat surprising in the light of the following experiments. 

 Whether there had really been no regeneration at all, or that I 

 had overlooked the new organs, or whether they may have dis- 

 integrated during the night following the death of the medusa I 

 am unable to say. Certain it is, however, that if regeneration 

 had gone forward as markedly as in the following cases one could 

 hardly have failed to distinguish it. I am inclined to believe 

 that the paralysis following the total removal of these organs 

 may have served to delay or inhibit active regeneration. 



The next series of experiments differed materially from the 

 former, particularly in that care was taken to retain certain of 

 the rhopalia in order to insure continued activity of the organisms 

 during the progress of the experiment. The number of rhopalia 

 retained varied from one to eight, the latter case serving as a 

 means of testing the relative influence of these bodies on the 

 behavior of the animals and the rate of regeneration. 



On May 12th several specimens, averaging only about half the 

 size of the preceding, namely, about 50 m/m in diameter, were 

 experimented upon. In the first one all the rhopalia were retained, 

 but marginal notches were made of varying sizes between the 



