226 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 



passive, except that every now and then one part 

 or another of the margin is suddenly contracted in 

 a semilunar form. By-and-by, however, even these 

 occasional twitches cease, and the animal is now 

 insensible to all kinds of stimulation. Recovery in 

 noi-mal water is gradual, and marked in its first 

 stage by the occasional retractions of the margin 

 last mentioned. At about this stage also, or some- 

 times slightly later, the animal first becomes respon- 

 sive to stimulation ; and it is interesting to note 

 that the response is performed, not by giving a 

 general spasm as would the unpoisoned animal, but 

 by folding in the part irritated — an action which 

 very much resembles, on the one hand, the spon- 

 taneous couA^ulsive movements just described, and, 

 on the other, the response which is given to stimu- 

 lation by the unpoisoned bell when gently irritated 

 after removal of its margin. After these stages 

 there supervenes a prolonged period of quiescence, 

 during which the animal remains normally respon- 

 sive to stimulation. Spontaneity may not return 

 for several hours, and, after it does return, the 

 animal is in most cases permanently enfeebled. 

 Indeed, on all the species of Medusre, nicotin, both 

 during its action and in its subsequent effects, is 

 the most deadly of all the poisons I have tried. 



9. Morphia. — The anjiesthesiating effects of mor- 

 phia are as decided as are those of chloroform. I shall 

 confine myself to describing the process of an53esthe- 

 siation in the case of Aurelia aurita in an extract 

 from my notes. "A very vigorous specimen, having 

 twelve lithocysts, was placed in a strong sea-water 



