CHAPTER III 



NATURAL PHENOMENA GROUP THEMSELVES IN 

 PARALLEL SERIES OF DIFFERENT SCALES OF 

 MAGNITUDE 



A SLIGHT consideration of the dimension of biological 

 phenomena has given us a glimpse of the importance of 

 questions concerning scales of magnitude in the objective 

 study of nature. The principle of continuity as we have 

 defined it allows us to look upon organic evolution as a 

 natural sequence of inorganic evolution ; it also obliges 

 us to ask ourselves at what particular point of inorganic 

 evolution we can reasonably place the appearance of life. 

 But to do this we must pass in rapid review inorganic evolu- 

 tion or, to use language without any hypothesis, the general 

 classification of natural phenomena. 



The principle of continuity is wonderfully verified in the 

 manifestations of inorganic activity taken altogether ; 

 but this is on condition that we do not try to bring every- 

 thing into a single series. On the contrary, we must con- 

 tent ourselves with verifying several parallel series with 

 different scales. 



It is a strange thing that nature, whom we like to think 

 so rich, has at her disposition so small a number of models ; 

 and these we find so like each other in the corresponding 

 terms of the parallel series that the mathematical formulae 

 applicable to one of the series can be used for the others 

 without any great modification. Even the modern theory 



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