4:72 EVENINGS AT THE MICKOSCOPB. 



the particies of carmine, foi* the internal vessels renaain 

 colourless. 



I have found that if a droiJ of water containing 

 these animals, be placed on a slip of glass exposed to 

 the open air, they do not burst as the water dries 

 away ; but dry flat on the glass, their bodies broader, 

 but shorter than when alive, and quite entire. Their 

 cilia are then very manifest. On being again wetted, 

 though after only a few minutes' desiccation, I have 

 never been able to revive them, nor any other Infu- 

 soria in like circumstances, notwithstanding what is 

 stated in books. 



Here is another species in equally amazing pro- 

 fusion, 8. mytilus. Its form is oblong, with rounded 

 extremities, the anterior obliquely dilated. This spe- 

 cies affords a good example of the various organs of 

 locomotion. A transparent oblong shield, which is 

 quite soft and flexible, is spread over the back, which 

 does not prevent the eye discerning all the organs 

 through it, though much more commonly the animal, 

 when under the microscope, crawls belly-upward, 

 beneath the glass cover of the live-box. Around 

 the anterior part, which is broadened, are placed cilia, 

 which are vibratile ; these ai'e continued round the 

 mouth, a sort of fold on the side. Towards the posterior 

 extremity on each side are other rows of cilia, which 

 being large are well displayed. On the ventral surface, 

 chiefly towards the front part, are seen several thick 

 pointed processes, shaped like the prickles of a rose, 

 but flexible, and capable of being turned every way. 

 These are the unoini, and are evidently used as feet, 

 the tips being applied to the glass. The optical effect 

 of the throwing about of these uncini, when the place 



