PLANARIA FLEXILIS. 



the sphere of the solar rays ; all the won- 

 derful operations of the bee are conducted 

 in the dark. Most planariae court the 

 light indeed ; but the flexilis rather inclines 

 to shun it, less, we may conjecture, from 

 being warned of its presence by the specks 

 or eyes, than from some disagreeable sen- 

 sation produced on the body. Apparently, 

 the vicinity of food is recognized more 

 from an analogous impression, whatever 

 sense may be affected, than from vision. 



The body is surrounded by a smooth 

 narrow margin, paler in colour than the rest, 

 and of a different texture, participating, in a 

 minor degree, of the gelatinous consistence 

 which composes the general substance of 

 the whole genus. From these character- 

 istics, the species can hardly be mistaken, 

 particularly as there is no other animal 

 known to us that resembles it. 



The size of each individual is materially 

 affected by the external temperature, and 

 the food absorbed. As the day is warmer, 

 the planaria is larger, and it sensibly di- 



