Characteristics of Rotifers. 285 



arranges his stones or bricks. There are also obvious and im- 

 portant differences between the ciliary apparatus of the Flos- 

 cales, which exhibit nothing" like rotation, and those of the 

 (Ecistes, Lvmnias, or Melicerta, which do show that remark- 

 able phenomenon, and in which it is subservient to the collec- 

 tion of food. In fact, Dujardin's order of fixed rotifers is so 

 far unnatural, that it groups together families that must be 

 separated in any system founded more upon structure and less 

 upon obvious peculiarities of external appearance. 



If we followed Dujardhr's arrangement, we should begin 

 by speaking of the Floscularians, which would not have been 

 called "rotifers" or wheel-bearers at all, if they had been the 

 first of the group to attract attention. The most con- 

 spicuous and decided wheel-bearer is the common rotifer, in 

 which the rotatory organs serve the two purposes of locomotive 

 engines and food collectors, and probably, also, act in assisting 

 respiration by bringing fresh currents of water to the delicate 

 tissues of the creature. When it pleases this rotifer to anchor 

 herself by her tail-foot, her mode of life for the time resembles 

 that of (Ecistes or Limnias. Her ciliary currents cause a con- 

 vergence of whirlpools, which bring all sorts of particles, living 

 or dead within her reach, and she selects some for reception and 

 others for rejection. This being ended, we find her swimming, 

 or crawling, frequently routing about with the snout- like ex- 

 tremity she presents when her wheels are withdrawn, and appa- 

 rently exerting discrimination in the selection of places to exa- 

 mine, and of food to take in. From this active, many-motioned 

 animal, with powerful, whirlpool machinery at her command, 

 let us pass to the beautiful Floscule, one of the most exquisite 

 of rotifers, when properly exhibited by dark-ground illumina- 

 tion. If our illuminating apparatus is nicely managed we see 

 an extremely delicate and transparent cylinder like a confec- 

 tioner's glass, surrounding the creature, and forming her house. 

 Slowly she rises, looking so uncouth that her appellation of 

 " beautiful " seems inappropriate. But we must not be in a hurry 

 to condemn her. Most gracefully she throws out her five lobes, 

 and opens from each one a long tuft of cilia, gleaming and 

 glancing in the light of our apparatus. If we keep quiet, the 

 fans remain expanded and still. Bach of the long hairs or cilia, 

 of which it is composed, appears capable of transmitting delicate 

 vibrations, and we frequently see a whole group of them twinlde 

 in succession like the small steel vibrators of a musical-box 

 when the instrument is playing. The animal can direct her 

 head to any quarter, she can change at will the position of her 

 richly- ciliated lobes, and thus cause the inward current which 

 she maintains by less conspicuous cilia to bring to her mouth the 

 particles she requires. Here the long cilia may be roughly 



