76 VORTICELL&. PART in. 



Infusoria are remarkable for the diversity of their re- 

 productive powers ; for, besides division and gemmation, 

 they are reproduced by a kind of alternate generation, 

 accompanied by singular metamorphoses. The Vorti- 

 cella, one of the most beautiful animals of its class, lives 

 in pools of fresh water : groups of them are found on 

 almost every mass of duckweed like little blue bells 

 upon slender stalks, creating active currents in the 

 water by the vibrations of long and powerful cilia with 



Fig. 107. Vorticdfee. 



which the margin of the bell is fringed. The lip or 

 edge of the bell is bent outwards into a permanent rim, 

 and a deep groove cleaves the rim on one side, in which 

 a wide cavity forming the mouth is placed. The mouth, 

 the short throat or gullet, and the whole bell, are bristled 

 with vibratile cilia. 



The Yorticellse feed on vegetable organisms, chiefly 

 diatoms, and are exceedingly voracious. The cilia round 

 the rim of the bell entangle the food, draw it into the 

 mouth, and those in the gullet force particle after 



