162 MARVELS OF POND-LIFE. 



vulgaris^) which, with several others of its tribe, 

 had been walking over the ccenoecium^ and swimming 

 amongst the tentacles, as if unconscious of danger. 

 All of a sudden it went down the whirlpool leading 

 to the mouth, was rolled up by a process that 

 could not be traced, and without an instant's loss of 

 time, was seen shooting down in rapid descent to 

 the gulf below, where it looked a potatoe-shaped 

 mass, utterly destitute of its characteristic 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 sup- 

 plied 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 crea- 



