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1.^^ 



CHAPTER I 



INTRODUCTION— GENERAL CHARACTERISTICS 

 OF LIVING MATTER 



It is a peculiarity of living matter, as distinguished 

 from non-living matter, that it is never found in a 

 diffuse, unorganized, or formless state, but always 

 composing definite individualized systems or organisms, 

 of which there are many kinds or species, each with 

 definite and, on the whole, highly constant physico- 

 chemical, structural, and active characters. These 

 organisms form a class of natural systems which, con- 

 sidered quantitatively, is a very small one in comparison 

 with physical nature as a whole. This fact in itself 

 implies that living systems are highly special develop- 

 ments; they represent a higher order of synthesis, and 

 it is to be expected that they should exhibit properties 

 and activities which are absent in non-living systems. 

 Hence the existence of a sharp contrast between the 

 living and the non-living — i.e., between organism and 

 environment — is not in itself surprising. We know, 

 however, that continuous transitions from the one to 

 the other have existed and stilL exist; life has evolved 

 from non-living matter in the past; and in the present 

 every living organism is the seat of a continual trans- 

 formation of non-living into living matter. The chief 

 problem of general physiology is to trace the steps of 

 this transition; i.e., to determine the nature of the 

 synthesis by which the living matter, protoplasm, is 



