Marvels of Pond-Life. 123 



teristic living form. Having been made into a bolus, 

 the unhappy rotifer, who never gave the faintest sign of 

 vitality, was tossed up and down from the top to the 

 bottom of the stomach, just as a billiard-ball might be 

 thrown from the top to the bottom of a stocking. 

 This process went on for hours, the ball gradually 

 diminishing in size, until at last it was lost in the 

 general brown mass with which the stomach was filled. 

 The bottom of the stomach seems well supplied with 

 muscular fibres, to cause the constrictions by which 

 this work is chiefly performed, and by keeping a colony 

 for a month or two, I had many opportunities of seeing 

 my Polyzoa at their meals. 



When alarmed the tentacles were quickly retracted, 

 but although these creatures are said to dislike the light, 

 and usually keep away from it in their native haunts, 

 my specimens had no objection to come out in a strong 

 illumination, and seemed perfectly at their ease. They 

 were indeed most amiable creatures, and never failed to 

 display their charms to admiring visitors, who rewarded 

 them with unmeasured praise. Twice I had an oppor- 

 tunity of observing an action I cannot explain, except 

 by supposing either that the tentacles of the Plumatella 

 have some poisonous action, or that rotifers are 

 susceptible of fear. On these occasions the common 

 rotifer was the subject of the experiment. First one 

 and then another got among the tentacles, and on 

 escaping seemed very poorly. One fellow was, to borrow 

 a phrase from Professor Thomas Sayers, " completely 

 doubled up," and two or three seconds — long periods in 

 a rotifer's life — elapsed before he came to himself again. 



