CHAPTER II 

 THE CELLULAR ORGANIZATION OF LIVING MATTER 



General physiology has been defined by Verworn^ 

 as '^ cellular physiology," in accordance with the general 

 conception of the cell theory that the ultimate living 

 units of any organism are the cells. According to this 

 conception the cells are the simplest units capable of 

 independent life; hence general physiology, aiming 

 at the anatysis and characterization of life-processes, 

 should be equivalent to cell physiology. There appears, 

 however, to be a certain arbitrariness in this idea. 

 The cell is already a complex system with a definite 

 organization, usually containing a nucleus and exhibiting 

 other special structural differentiations. The question 

 of the physiological significance of the cellular organiza- 

 tion constitutes a special problem in itself. While it 

 is remarkable that all higher organisms show this type 

 of organization, it seems hardly justifiable to regard all 

 organisms as consisting of cells and products of cells. 

 Such a conception regards the simplest living unit as 

 having a certain definite type of structural organization; 

 i.e., it is essentially a morphological conception. A 

 chemical characterization seems to meet the requirements 

 of the case more completely. Many organisms are 

 known which do not show the chief structural feature of 

 the cell, differentiation into nucleus and cytoplasm; e.g., 

 bacteria and blue-green algae. Usually bacteria are 

 regarded as plant cells of a special kind; it is question- 



' Allgemeine Physiologic, 5th edition, Jena (1909), chap. i. 



14 



