THE CRITERIA OF LIVINGNESS 81 



I. Self-disassimilation. 



II. Self-preservation, including assimilation, growth, movement, 

 feeding, etc. 



III. Self-multiplication. 



IV. Self-development. 



V. Self-regulation in the exercise of all functions, including 

 self-differentiation, self-adjustment, self-adaptation, and 

 in many organisms distinctly recognisable psychical func- 

 tions. 



It is very interesting to notice how this hard-headed founder 

 of what he calls " developmental mechanics " speaks deliber- 

 ately of self-preservation, self-increase, self-differentiation, 

 self-regulation, and so on. 



The statement we propose differs a little from this and 

 from others, being an attempt at a logical grouping of the 

 fundamental characteristics. 



3. Persistence of a Complex Specific Metabolism and of 

 a Corresponding Specific Organisation. 



The image of the organism is the burning bush of old ; 

 it is all afire, yet it is not consumed. Nee tamen consumeba- 

 tur. Or it is like the sunlit top of a fountain rising in 

 the air; its component elements are restlessly changing on 

 their way up or on their way down, yet the form remains 

 approximately the same. The peculiarity is not that the or- 

 ganism is in continual flux, for chemical change is the 

 rule of the world ; the characteristic feature is, that the 

 changes in the organism are so regulated and balanced that 

 the integrity of the creature is retained. The great English 

 physiologist, Sir Michael Foster, used to say that " A living 

 body is a vortex of chemical and molecular change " ; and 

 the image of a vortex expresses the fundamental fact of 

 persistence in spite of ceaseless change. 



