170 NATURAL HISTORY 



On the morning of the 24th of December, I selected 

 some very fine specimens of these creatures, and having 

 laid them on the stage- glass of a microscope, I covered 

 them with a thin plate of mica : at the end of two hours 

 they appeared lively, but when examined four hours after- 

 wards, all the water being evaporated, no signs of life 

 could be detected, even under a powerful Achromatic 

 Microscope : in this state they were left until the evening 

 of the following day, when, upon being re-examined, 

 they had shrunk, and were apparently quite dead. I 

 then supplied them with a drop of water, and in a few 

 minutes their bodies began to extend themselves upwards: 

 their tails, which were not perceptible before, became 

 protruded, and they began to elongate and contract them- 

 selves repeatedly, increasing at each succeeding action 

 until they had recovered the perfect freedom of their 

 muscles, and at last, when the use of their rotatory or- 

 gans was restored, they swam away. The time taken up 

 in their resuscitation was about ten minutes, but those 

 possessing ova required a longer period. It is remarked 

 that in the young produced from ova, the manducatory 

 and rotatory organs first exhibit signs of vitality : in the 

 case of resuscitation, these organs revive the last. Size, 

 l-30th to 1 -400th. 



397. VoRTfCELLA enjtJirophthaima {Philodina, E.) — 

 This creature has not been described by any writer ex- 

 cept Dr. Ehrenberg, who enumerates three species, under 

 the generic name Philodina, from their love of whirling. 

 The one under notice, the red-eyed Philodina, is shewn 



