ROTIFERS. 



453 



fix themselves to extraneous substances ; while the cilia 

 is in rapid motion, this prevents the anterior portion of 

 the body being drawn in by the force of the rotatory 



Fig. 228. 



1, The common Wheel-Animalcule, Rotifer vulgaris, with its cilia or rotators 

 b, protruded ; c, its horn ; d, oesophagus ; e, gut ; /, outer case ; g, eggs. 2, The 

 same in a contracted state, and at rest : at g is seen the development of the 

 young. 3, Pitcher-shaped Brack/onus: a, its jaws; b, shell; c, cilia, or rota- 

 tors : d. tail 4. Bakers Brachionus : a, the jaws and teeth ; b, the shell ; c, 

 the cilia ; e, the stomach. 



action. They multiply by eggs ; a few have been seen to 

 bring forth their young alive. In the atmosphere the eggs 

 have been discovered whirling along by the force of the 

 wind to some resting-place, where, when circumstances 

 admit, they spring into active life, and fulfil their appointed 

 destiny. The eggs are of an oval form, and some ten, 

 twenty, or thirty may be seen in an animal, of a brown 

 colour, others are of a delicate pink and deep golden yel- 

 lo\r. In those of a light colour, the young are sometimes 



