42 OX THE EDUCATIONAL VALUE ii 



able rapidity by means of the vibrations of the 

 long filament of cilium. 



Nor is the amount of chemical energy which 

 the little creature possesses less striking. It is a 

 perfect laboratory in itself, and it will act and re- 

 act upon the water and the matters contained 

 therein; converting them into new compounds re- 

 sembling its own substance, and at the same time 

 giving up portions of its own substance which have 

 become effete. 



Furthermore, the Euglena will increase in size; 

 but this increase is by no means unlimited, as the 

 increase of a crystal might be. After it has grown 

 to a certain extent it divides, and each portion 

 assumes the form of the original, and proceeds to 

 repeat the process of growth and division. 



Nor is this all. For after a series of such divi- 

 sions and subdivisions, these minute points assume 

 a totally new form, lose their long tails — round 

 tliemselves, and secrete a sort of envelope or box, 

 in which they remain shut up for a time, eventu- 

 ally to resume, directly or indirectly, their primi- 

 tive mode of existence. 



Now, so far as we know, there is no natural 

 limit to the existence of the Euglena, or of any 

 other living germ. A living species once launched 

 into existence tends to live for ever. 



Consider how widely different this living par- 

 ticle is from the dead atoms with which the physi- 

 cist and chemist have to do! 



