ARTIFICIAL IllIYTHM. 187 



Coming, then, to experimental tests, we have 

 already seen that in the deganglionated swimming 

 organ of Anrclia aiirita, rhythmic response is yielded 

 to constant faradaic stimulation of low intensity. 

 The next question, therefore, which presents itself 

 in relation to our subject is as to whether other 

 modes of constant stimulation elicit a similar re- 

 sponse. Now, in a general way, I may say that 

 such is the case, although I have chosen faradaic 

 stimulation for special mention, because, in the first 

 place, its effect in producing rhythmic action is the 

 most certain and precise; and, in the next place, 

 the effects of administering instantaneous shocks 

 at given intervals admit of being compared with 

 the effects of constant faradaic stimulation better 

 than with any other kind of constant stimulation. 

 Nevertheless, as just stated, other modes of con- 

 stant stimulation certainly have a more or less 

 marked effect in producing rhythmic response. The 

 constant current, during the whole time of its 

 passage, frequently has this effect in the case of 

 the paralyzed nectocalyx of Sarsia ; and dilute spirit, 

 or other irritant, when dropped on the paralyzed 

 swimming organ of Aurelia aurita, often gives rise 

 to a whole series of rhythmical pulsations, the sys- 

 toles and diastoles following one another at about 

 the same rate as is observable in the normal swim- 

 ming motions of the unmutilated animal. 



From this it will be seen that, both in the case 

 of mechanical and of chemical stimulation, the same 

 tendency to the production of rhythmic response 

 on the part of the paralyzed tissues of Aurelia may 



