THE HYDRA AND JELLY-PISS. 27 



victim, which is instantly paralyzed, and thus falls an easy 

 prey to its captor. These nettling organs are found in all 

 Hydras, jelly-fishes and polyps. 



The Hydra, like some other animals of simple structure, 

 is capable to a wonderful degree of reproducing itself when 

 cut into pieces. Trembly, as early as 1744, not only cut 

 H} r dras into two, each part becoming a perfect Hydra, but 

 on slicing them across into thin rings he found that from 

 each ring grew out a crown of tentacles; he split them into 

 longitudinal strips, each portion becoming eventually a well- 



FIG. 22. Colony of Hydractinia on a shell tenanted by a hermit-crab. 



(Natural size ) 



shaped Hydra, and finally he turned some inside out, and 

 in a few days the Hydra swallowed and digested bits of 

 meat, its former stomach-lining having now become its skin. 

 The Hydra reproduces by budding as well as by eggs. 



The process of budding is but a modification of that in- 

 volved in natural self -division, and it is carried on to a 

 great extent in Hydra, a much larger number of individuals 

 being produced in this way than from eggs. Our figure 

 (21) shows two individuals budding out from the parent 



