THE SPECIFIC CHARACTERISTICS OF VITALITY 547 



That living matter is able to transform energy and is itself 

 highly unstable, chemically speaking, need not compel us to 

 regard it as precisely in the same category as certain other 

 much more stable forms of matter which also are able to 

 transform energy. 



The following enumeration of the properties of protoplasm 

 or living matter would probably be disputed by no philo- 

 sophical biologist as constituting the characteristics of the 

 highest (mammalian) type of protoplasm. 



1 . The possession of affectability (irritability) ; 



2. The possession of functional inertia ; 



3. The power of transmuting the chemical energy of food 



into the kinetic forms of heat, movement, nerve 

 energy, electric current, and sound. 



4. The power of assimilating matter which is chemically 



unlike the living substance, and of growing thereby. 



5. The power of producing, under the influence of foreign 



substances or poisons, certain anti-bodies (anti-toxins, 

 or ferments) designed to render the former innocuous. 



6. The power of reproduction, that is to cast off an organism 



capable of independent existence which shall per- 

 petuate the parental type. 



7. The power or propensity to evolve, from a relatively 



simple microscopic layer of cells, all the highly dif- 

 ferentiated tissues and systems of the adult body. 



Now it is undeniable that some of these characteristics of 

 livingness are also possessed by matter which is not living 

 and has never lived. For instance, affectability or irritability, 

 found in every text-book of physiology as a property of living 

 matter, is certainly a property of such lifeless matter as gun- 

 powder or dynamite and of many another unstable chemical 

 substance. Gunpowder has affectability towards the stimulus 

 of a spark, and dynamite has affectability towards the stimulus 

 of concussion, for affectability is but the power of responding 

 to a stimulus. 



Similarly functional inertia — or the power of non-response 

 to a stimulus — is a property possessed both by living and by 

 non-living matter. In living matter it is the property by 

 which limits are set to its activity, by which it is made insus- 

 ceptible to certain stimulations, by which rates of response 



