44 ON THE EDUCATIONAL VALUE n 



remaining the same) this spontaneity of action 

 if I may use a term which implies more than I 

 would be answerable for which constitutes so 

 vast and plain a practical distinction between 

 living bodies and those which do not live, is an ulti- 

 mate fact ; indicating as such, the existence of a 

 broad line of demarcation between the subject- 

 matter of Biological and that of all other 

 sciences. 



For I would have it understood that this simple 

 Euglena is the type of all living things, so far as 

 the distinction between these and inert matter is 

 concerned. That cycle of changes, which is con- 

 stituted by perhaps not more than two or three 

 steps in the Euglena, is as clearly manifested in 

 the multitudinous stages through which the germ 

 of an oak or of a man passes. Whatever forms 

 the Living Being may take on, whether simple or 

 complex, production, growth, reproduction, are the 

 phenomena which distinguish it from that which 

 does not live. 



If this be true, it is clear that the student, in 

 passing from the physico-chemical to the physio- 

 logical sciences, enters upon a totally new order of 

 facts ; and it will next be for us to consider how 

 far these new facts involve new methods, or require 

 a modification of those with which he is already 

 acquainted. Now a great deal is said about the 

 peculiarity of the scientific method in general, and 

 of the different methods which are pursued in the 



