OF ANIMALCULES. 163 



dition : figure 258 gives the same in its contracted 

 form : both of which are taken from drawings by Dr. 

 Ehrenberg. 



This creature is enveloped in a double tunic, or coat, of 

 a soft gelatinous substance. The fore extremity of the 

 body is abruptly truncated, and furnished with seventeen 

 muscular bodies of a globular form (only five of which 

 are exhibited in the drawing) . These are disposed in two 

 concentric circles, their upper surfaces being furnished 

 with several strong cilia, and their lower extremities con- 

 nected by means of ligaments to muscular balls (a), so as 

 to permit them to rotate, thereby enabling the cilia to 

 produce a current in the ambient water towards the 

 mouth, which is situated in the centre. At the entrance 

 of the mouth and oesophagus is disposed on each side a 

 series of indentations, or teeth, which are exhibited in 

 situ, figure 259. ^^ These are hard bodies, not edged in 

 front, but bluntly pointed, which in their junction ap- 

 pear like the fingers of a hand, and are five in number on 

 each side." In the common wheel animalcule (396), 

 I have observed only three on each side, but they are 

 larger, and very distinct, even while the creature is living. 

 These teeth are fixed to the large muscular body (6), which 

 possesses the power of alternately opening and closing, 

 and the food passes through it into the alimentary 

 canal (c c), in which are shewn several small animalcules 

 (viz. Naniculafuha and N. gracilis, page 58), that have 

 been swallowed : this canal terminates at {d), and wil^. _^ 

 the glands (e) complete the digestive apparatus. A^ ©5^^/ 





