152 NATURAL HISTORY 



also produced by buds, similar to the armed pohjj)e^ 

 (see fig. 212.) 



The next method of propagation is by a division of the 

 parent. When this is to be effected longitudinally, the 

 bell increases in breadth, and presents the form of figure 

 203 : a separation then commences, and double circles 

 of cilia are formed -, the body of the animal then divides, 

 and other cilia grow around the dome of the bell, assum- 

 ing the appearance of figure 220 : by constantly whirling, 

 one or both* of the bells separate from the stem, and 

 swim about, in wiiich condition they have been classed, 

 as a distinct genus, under the name Urceolaria. Should 

 it happen that both the bells are twisted oiF, the stem re- 

 mains stationary, and does not contract afterwards, or 

 produce a new bell. The most striking peculiarity which 

 presents itself next is, that the end formerly attached to 

 the stem swims foremost, and from the other end pro- 

 ceeds the new stem : before, however, this is effected, it 

 changes its form, and sometimes buds out or separates. 

 Figures 217 and 219 show them soon after separation ; 

 the latter is the genus Ec/issa, of Schrank, and the for- 

 mer, with the small protuberance, Rinella, of Bory St. 

 Vincent. If the creature retain its bell-shape, be not 

 inverted, and exhibit the lower cilia, as figure 222, it 

 forms the genus Kerohalina of the latter naturalist ; and 

 when all the cilia are invisible, as figure 221, then he 

 calls it the genus Craterina. Again, it constitutes the 



* Microscopic Cabinet, plate 7. 



