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



On Tiaropsis indicans this poison has the effect 

 of causing a general spasm, Avhich would be undis- 

 tinguishable from that which in this species results 

 from general stimulation of any kind, were it not 

 that there is a marked difference in one particular. 

 For in the case of strychnia poisoning, the spasm, 

 while it lasts, is not of uniform intensity over all 

 parts of the nectocalyx ; but now one part and now 

 another part or parts are in a state of stronger 

 contraction than other parts, so that, as a general 

 consequence, the outline of the nectocalyx is con- 

 tinually changing its form. Moreover, in addition 

 to these comparatively slow movements, there is a 

 continual twitching observable throughout all parts 

 of the nectocalyx. Each individual twitch only 

 extends over a small area of the contractile tissue ; 

 but in their sum their effect is to throw the entire 

 organ into a sort of shivering convulsion, which is 

 superimposed on the general spasm. After a time 

 the latter somewhat relaxes, leaving the former 

 still in operation, which, moreover, now assumes a 

 paroxysmal nature — the convulsions consisting of 

 strong shudders and frequent spasms with occasional 

 intervals of repose. 



In the case of Tiaropsis diademata the action of 

 strychnia is very similar, with the exception that 

 there is no continuous spasm, although occasional 

 ones occur amid the twitching convulsions. After 

 a time, however, all convulsions cease, and the 

 animal remains quiescent. While in this condition 

 its reflex excitability is abnormally increased, as 

 shown by the fact that even a gentle touch will 



