12 PLANARIA FLEXILIS. 



ter was changed, and a quantity of mud put 

 into a glass jar along with them. Next 

 morning a material alteration had ensued : 

 the colour of the largest was altogether al- 

 tered from its original dull and tawny 

 white, to dark reddish brown. Numerous 

 ramifications, beautifully interlaced, were 

 distributed throughout the body, proceed- 

 ing from the centre to the interior of the 

 narrow margin, into which they did not pe- 

 netrate, and the size of the body was aug- 

 mented. This could be ascribed to the 

 quality of the food alone ; and it also 

 shewed, that the animal was carnivorous. 

 Other experiments followed ; and some 

 time afterwards, the same planaria? having 

 devoured a green marine nereis, a creature 

 of soft consistence as themselves, their bo- 

 dies became of a greenish hue, which three 

 or four days were required to obliterate. 

 It is alike with each variety of food : the 

 colour is constantly imparted to the animal ; 

 and nothing can be more elegant and inte- 

 resting than its dissemination among the 



