POISONS. 225 



irritability had supervened, recovery began in ten 

 minutes after rc-iunnersion, and was cumplete in 

 lialf an Lour. 



In Tiaropsis the symptoms of nicotin poisoning 

 are also well marked. When gradually adminis- 

 tered, the first effect of the narcotic is a complete 

 loss of co-ordination in the swimming motions. A 

 sli!_dit increase of the dose brino-s about a tonic 

 spasm, which differs from the natural spasm of 

 these animals — (a) in being stronger, so that the 

 nectocalyx becomes bell-shaped rather than square, 

 (b) in being much more persistent, and (c) in under- 

 going variations in its intensity from time to time, 

 instead of being a contraction of uniform strength ; 

 thus the spasm temporarily affects some parts of 

 ijke nectocalyx more powerfully than other parts, 

 so that the organ may assume all sorts of shapes. 

 Such distortions proceed even further under the 

 influence of nicotin than under that of strychnine, 

 etc. Sometimes, for instance, one quadrant will 

 project in the form of a pointed promontory; at 

 other times two adjacent or opposite quadrants 

 will thus project, and occasionally all four will do 

 so, the animal thus becoming star-shaped. Some- 

 times, again, one quadrant will be less contracted 

 than the other three, while at other times more or 

 less slight relaxations affect numerous parts of the 

 bell, its margin being thus rendered sinuous, though 

 more or less violently contracted in all its parts. 

 This state of violent spasm lasts for several minutes, 

 when it gradually passes off, the nectocalyx relaxing 

 into the form of a deep bowl and remaining quite 



