GENERAL BIOLOGY 



CHAPTER I 



LIVING SUBSTANCE 



BIOLOGY, the "science of life," includes in its 

 broadest aspects the investigation of all that per- 

 tains to the structure and functions of living things. 

 The observing and recording of the wonderful 

 variety of Nature will always have a fascination 

 not only for the poet, but for the scientist as well. 

 But the latter is more especially concerned with 

 the meaning, the analysis, or the explanation of 

 natural phenomena. Philosophy tells us that 

 science can never hope to get the ultimate 

 explanation of anything which it observes. All 

 that it can do is to reduce the complexities to simpler 

 expression, to find the common denominator for 

 things that seem .at first glance unrelated, in the 

 same way that the mathematician by processes of 

 factoring reduces elaborate and complex algebraic 

 expressions to simple statements of relation. And, 

 just as in mathematics, the greater the number of 

 variables we have to deal with, the more involved and 

 difficult becomes our computation, so in physical 

 and biological science the greater the number of 



