PLANARIA FELINA. 45 



of a very minute planaria, subjected to the 

 microscope, disclosed twenty-four. The 

 real purpose of these characteristics, I have 

 not bpen more successful in establishing, 

 than their use in other species. But it 

 may, perhaps, be less difficult to institute 

 a series of experiments with that view on 

 the felina, than on those planariae where 

 they are not equally conspicuous. 



Protected by its native element, the pla- 

 naria felina reposes inactive on the inner 

 surface of aquatic plants, on fragments of 

 decaying wood, or the under part of stones. 

 It can with difficulty be dislodged from 

 crevices where it takes up its abode, per- 

 tinaciously adhering to different substan- 

 ces, until removed by a soft feather, or 

 washed off by repeated immersion in wa- 

 ter. The societies in which it lives, in-, 

 elude those of every age ; and should the 

 fluid containing them accidentally evapo- 

 rate, all appear crowded together, contract- 

 ed into a small regular ellipse. If a num- 

 ber be confined in a glass vessel, the whole 



