102 THE AQUARIAN NATURALIST. 



point, soon falls off into the surrounding element, but 

 not to perish immediately; demonstrations of life 

 continue during many hours ; nay, they are protracted 

 for eight days or longer in vigorous specimens. Some 

 analogy with the form of the simple Hydra may be 

 now recognized in this separated portion; but the 

 short stump under the head, which is drawn from the 

 stalk by separation, and represents the body of the 

 Hydra, has no power of adhering to foreign objects ; 

 nor are the feelers of that extensile nature, nor pre- 

 hensile power, which characterize those of the Hydra 

 proper. 



Meantime the florid summit of the vacant stalk 

 becomes pale and appears to be fading; a kind of 

 cicatrix closes the wound. But after the lapse of a 

 certain interval, it darkens again, and an internal bud 

 is seen advancing, which speedily ascending, bursts the 

 transparent skin and flourishes a new head, springing 

 precisely from the same point whence its precursor 

 had fallen, and of equally vivid hue. 



Singular to be told, the regenerative faculty is not 

 exhausted here ; for after continuing to flourish during 

 an indefinite period, this second head droops and dies, 

 and is dissolved like its predecessor. Then it is re- 

 placed by a third, and the third by a successor. How 

 often the like may be repeated, how many successive 

 heads may be generated anew during the whole life 

 of the zoophyte, cannot be readily ascertained. 



Some remarkable facts attend this renewal of the 

 head : the prolongation of the stem seems absolutely 

 dependent upon it : having lost its head, the stem to 

 all appearances remains unchanged, unless in the cir- 



