1 12 THE BEGINNINGS OF LIFE. 



rock-pool whose body has been accidentally torn, and 

 let us think of the powers of repair possessed by each 

 it is not killed, and an attempt will be made more or 

 less effectually to reproduce the lost parts, just as a 

 crystal, in its own proper medium would, after injury, 

 tend to reproduce its original symmetry of form. Look 

 again at the little polyp of our lakes and ponds the 

 Hydra, whose individual Life is so dwarfed in com- 



FIG. 2. Hydra viridis in different stages of extension and contrac- 

 tion, reproducing gemmiparously attached to roots of Duckweed. 

 (Roesel.) 



parison with the Life of its several parts that you may 

 cut it or injure it to almost any extent, and yet the 

 separate parts will still live \ It can, in fact, scarcely 



1 It has, moreover, been recently revealed by the experiments of 

 Haeckel that a similar power of reproduction, previously unsuspected, is 

 possessed by Medusae. Haeckel says : ' My experiments proved that it 

 prevails to an amazing extent in many medusae, especially in those be- 



