VARIOUS MODES OF REPRODUCTION. 127 



cate thin film, including twin buds. These are un- 

 equally advanced; but as the lower one becomes 

 matured, its higher companion forks off, and then 

 another is developed from this latter in the same 

 manner. The buds are nascent Hydrae in their re- 

 spective cells, each having apparently its own peculiar 

 integument within the common filmy involucrum. 



Rapid growth ensues. A young specimen with 

 only a single head on the 4th of October, had ac- 

 quired six on the 20th, besides a seventh in embryo ; 

 and of course, as the extent of the zoophyte increases, 

 and the branches become more numerous, the evolu- 

 tion of additional polyps becomes proportionably more 

 rapid. 



The multiplication of these elegant zoophytes ap- 

 pears therefore to take place in three different modes : 

 1st, by cuttings, as in plants; 2ndly, by offshoots, or 

 the formation of new branches bearing polyps; and 

 Srdly, by Planulce, capable of locomotion. 



The first mode strikingly resembles what is ob- 

 served in the vegetable kingdom ; for as every branch 

 of the plant-like body contains all the parts necessary 

 for independent existence, it can hardly be a matter 

 of surprise, that any portion separated from the rest 

 will continue to grow and thrive as well as the entire 

 colony. 



The second mode of increase, namely, by the for- 

 mation of new branches and polyps, seems more like 

 the growth of a plant than the development of an 

 animal ; while the third is evidently specially intended 

 for the diffusion of the species. 



