174 JELLY-FJSH, STAll-FlSlI, AND SEA-URCHINS. 



Eventually the swimming motions entirely cease ; 

 but almost immediately after the animals are 

 restored to normal sea-water, they recover them- 

 selves completely, the rate and regularity of their 

 rhythm being then quite natural. The suddenness 

 with which this return to the normal state of 

 things is effected cannot but strike the observer as 

 very remarkable, and I may menti(m that it takes 

 place with equal suddenness at whatever stage in 

 the above-described process of asphyxiation the 

 transference to normal sea- water is accomplished. 



