20 DARWINIAN AND SPENCERIAN 



that particular constitution conferring upon them that 

 stable instability known as life. If selection there has 

 been, it may safely be asserted that the agency was 

 physical, i.e. the inorganic environment. During that 

 period — ^probably extending over geological ages — when 

 lifeless carbon compounds were giving rise to living carbon 

 compounds there can have been no struggle for life with 

 competing organisms. The survival of the simplest types 

 of living carbon compounds may thus be as referable to 

 chemical constitution as the isolability of a definite 

 synthetical compound. From this point of view the 

 question that has to be answered is, what particular 

 atomic configuration or configurations potentially vitaliz- 

 able were capable of existence under the environmental 

 conditions of that remote past ? ^ Given such compounds, 

 and the subsequent course of organic evolution by the 

 Darwinian process becomes intelligible. 



The physical condition which in one direction limits 

 the existence of such compounds is, of course, temperature. 

 The chemical Condition requires an atomic grouping of 

 sufiftcient stability to exist as a definite molecule or 

 molecular aggregate, and of sufficient instability, i.e. 

 internal mobility, to resist destructive physical and 

 chemical processes. In other words the compound must 

 be possessed of the faculty of ' responsivity ' with respect 

 to its environment.^ It would be rash to attempt to 



• This assumes that the passage from lifeless to living matter took 

 place only during past ages and is not taking place now. See, per contra, 

 note, p. i8. The supposition that life germs may be developing now, 

 here or elsewhere, makes no difierence to the above statement of the 

 question excepting the substitution of ' are ' for ' were ' and ' present ' 

 for ' remote past '. 



' The word environment is here used in its widest possible sense 

 as including the vital processes of assimilation and growth, in their 

 initial stages. For growth may be regarded as the result of the addition 

 of one carbon compound to another with which it is capable of com- 

 bining by virtue of its chemical constitution, i. e. assimilation as the 

 result of the action of one carbon compound upon another the inter- 

 action of an organic environment and a responsive organic compound. 

 Reproduction, as Spencer has shown, follows from growth. The term 

 ' mobility ' is used above in its chemical sense as referring to intra- 



