104 



an actinia and get off again quite uninjured ; it may even for a time 

 nestle among the tentacles with as much impunity as if it were only 

 in contact with a piece of sea- weed ; but should the tadpole have the 

 misfortune to fall in with a more voracious actinia, the reception it 

 meets with is very different. Sometimes, when by an incautious lash of 

 its tail it touches even a single tentacle, it may at once be laid hold 

 of, and in the violent efforts which it forthwith makes to break loose, 

 often merely brings itself within the reach of other tentacles, by 

 which it is seized and overpowered. Occasionally, however, after 

 having been thus seized, the tadpole by its superior activity succeeds 

 in effecting its escape, and when it does so, it seems for a time sin- 

 gularly excited ; it twists and writhes and wriggles through the 

 water, so as to leave no doubt that some very remarkable influence has 

 been exerted upon it. 



These observations are no doubt familiar to all who have studied 

 the habits of these animals ; for although the tadpole seems more 

 susceptible of the peculiar stimulus which the actinia can com- 

 municate than most of those creatures which are ordinarily cast in 

 its way, yet the same occurrences take place with the small crus- 

 taceans, &c. which are abundant in sea-water. Indeed no very close 

 attention is necessary to perceive, that while on some occasions these 

 little animals may creep to and fro over the surface and among the 

 tentacles of the actinia, at other times they are seized and killed with 

 the greatest promptitude. 



It remained to be determined what is the exact nature of the 

 power which the actinia has been thus found to have under its con- 

 trol. If it seized its victim by a simple mechanical effort, why 

 should the tadpole be so agitated for some time after having 

 escaped from its grasp? No peculiarly viscid secretion could be 

 detected on the tentacles, nor could any decided reaction be discerned 

 on their surface differing from the feebly alkaline condition of the 

 sea-water }n which they were placed ; moreover, the power of the 

 actinia seemed often to be exerted with too much promptness to be 

 compatible with the notion of the formation of a poisonous or sting- 

 ing fluid over its surface. 



On the hypothesis that it is an electrical power with which the 

 actiniae are endowed, it is obvious that the existence of animal elec- 

 tricity in them ought to be experimentally demonstrable by its 



