54> PLANARIA FELINA. 



paration, a new head prepares to vegetate 

 from before; and all the subordinate organs 

 are successively developed. But during its 

 advances to perfection, this regenerating 

 animal cannot be known to pertain to its 

 proper species ; and on slight, nay, on at- 

 tentive inspection, no one would hesitate 

 in pronouncing it different. The vacuity 

 that formed the recess of the heart is soon 

 filled up by a reproducing substance, from 

 which a clear light-coloured papilla next 

 arises, and gradually protrudes into a 

 long slender organ, while the general shape 

 and size of the original fragment are re- 

 tained. Thus a clumsy and distorted ani- 

 mal is presented, equally remote from the 

 parent whole, from the portion detached, 

 and from the figure which it will ultimately 

 attain. But in progress of time, the dia- 

 meter of the body decreases ; the regene- 

 rating protrusion is enlarged ; its extremity 

 is fashioned into a head ; the eyes and ten- 

 tacula appear; all the parts are bounded 

 by a regular outline ; a perfect animal is 



