Evolution 



that we cannot hope for any very definite conceptions as to the 

 nature of life. Broadly, however, the majority of physiologists 

 regard life as a highly intricate series of purely physical and 

 chemical processes, and if such a view be accepted, there is no 

 insuperable objection to a general theory of the origin of living 

 from non-living matter. By this it is not intended to imply that 

 the manufacture of living matter is an immediate possibility ; 



Fig. 1 6. — A typical cell (greatly magnified). 

 {k) Nucleus ; {p) cell protoplasm. 



for even according to such a theory as we have indicated, it would 



be supposed that living substance came into being by a very slow 



process of Evolution, which it is hardly conceivable could ever 



be repeated in the laboratory. Knowing, as we do, that there 



was a time when no life existed upon the earth, and believing, as 



there is good reason to believe, that there is no fundamental 



distinction between living processes and ordinary chemical and 



physical reactions, we may logically regard life itself as a product 



of a natural process of Evolution. 



24 



