596 THE ZOOPHYTES. 



brought into contact will quickly unite, and form 

 one animal, though each section belong to a differ- 

 ent species. The head of one species may be en- 

 grafted on the body of another. When one Polype 

 is introduced by the tail into another's body, the two 

 heads unite, and form one individual. Pursuing 

 these strange operations, M. Trembley gave scope 

 to his fancy, and, by repeatedly splitting the head 

 and part of the body, formed hydras more compli- 

 cated than ever struck the imagination of the most 

 romantic fabulists. 



These creatures continue active during the greatest 

 part of the year, and it is only when the cold is most 

 intense that they feel the general torpor of nature. 

 All their faculties are then for two or three months 

 suspended ; but if they abstain at one time they 

 have ample amends in their voracity at another ; 

 and, like all those animals that become torpid in 

 winter, the meal of one day suffices for several 

 months. 



