EXPERIMENTAL STUDIES UPON 

 HYDROMEDUSAE. 



C. W. HARGITT. 



SYRACUSE UNIVERSITY, SYRACUSE, N.Y. 



IN connection with previous work on regeneration the prob- 

 lem of animal grafting was repeatedly suggested by many 

 phenomena associated with that work, and during the summer 

 of 1898 a series of experiments was undertaken at the Marine 

 Biological Laboratory and carried on through the months of 

 July and August. 



It is a pleasure in this connection to acknowledge many 

 courtesies extended by the director, Prof. C. O. Whitman, 

 and valuable suggestions from Dr. Jacques Loeb, during the 

 progress of the work. The following paper aims simply to 

 present a resume of methods and results, deferring speculative 

 considerations which might be suggested by any of the phe- 

 nomena involved. 



I. Material. 



This was restricted to two sorts of organisms, Hydroids and 

 Medusae. Of Hydroids an almost unlimited amount and of 

 many genera and species were available and easily obtained 

 from the waters about the clocks of the U. S. Eish Commis- 

 sion, from the rocks and fucus in the harbor and adjacent 

 waters. It was obtained fresh every morning and experiments 

 were made only upon it within a few hours. The genera used 

 in the experiments were Eudendrium, Pennaria, Parypha, and 

 a few of the Campanularidae. 



Of Medusae only one species was available in sufficient 

 abundance and size for experimentation, namely, Gonionemus 

 vertens, a Medusa occurring in considerable numbers in the 

 "eel pond," a small body of water adjacent to the laboratory 

 and communicating with the waters of the harbor by a very 



/ 



35 



