XVII THE METHOD OF ORGANIC EVOLUTION 355 



is therefore a final proof that the accepted hypothesis is 

 inadequate " (page 568), and after sev^eral more pages of 

 illustration and argument, the final conclusion is reached 

 that — " it is quite certain that the distinctness and Dis- 

 continuity of many characters is in some unknown way a 

 part of their nature, and is not directly dependent upon 

 Natural Selection at all." 



Before going further, it will be well to make a few 

 observations on these very definite and positive conclusions 

 at which Mr. Bateson has arrived ; and it must be remem- 

 bered that this volume deals only with one portion of the 

 subject even of discontinuous variation, which is itself, if 

 we exclude monstrosities, only a small fragment of the 

 whole subject of variation. The impression that will be 

 produced on those who have given special attention to the 

 relations of living organisms to each other and to their 

 inorganic environment, will be that of an academic dis- 

 cussion, dealing to a large extent with words rather than 

 with the actual facts of nature. The author's main point, 

 that species form a discontinuous series, and that specific 

 differences cannot therefore have been produced by any 

 action of the environment, because that environment is con- 

 tinuous — an argument which, as we have seen, he dwells 

 upon and reiterates with emphasis and persistency — rests 

 wholly upon the obvious fallacies that in each smgle 

 locality the environment of every species found there is 

 the same, and that all change of environment, whether in 

 space or time, is continuous. To take this latter point 

 first, nothing can be more abrupt than the change often 

 due to diversity of soil, a sharp line dividing a pine or 

 heather-clad moor from calcareous hills ; or to differences of 

 level, as from a marshy plain to dry uplands ; or, for aquatic 

 animals, from the open sea to an estuary, or from a non- 

 tidal stream to an isolated pond. And when, in the course 

 of geological time, an island is separated from a continent, 

 or volcanic outbursts build up oceanic islands, the immi- 

 grants which reach such islands undergo a change of 

 environment, which is in a high degree discontinuous 



Even more important, perhaps, is the fact that every- 

 where, the environment as a whole is made up of an 



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