XVII THE METHOD OF ORGANIC EVOLUTION 377 



actual facts of nature. Mr. Bateson's discontinuous varia- 

 tions were long ago rejected by Darwin as having no impor- 

 tant part in the formation of new species, while recent and 

 ever-growing proofs of the generality and the magnitude 

 of individual variability, render these larger and rarer 

 kinds of variation of even less importance than in his 

 time. Mr. Galton's theory of organic stability, which is 

 essential to the success of discontinuous variations, has 

 been shown to be founded upon a comparison of things of 

 a totally dissimilar nature, and, further, to be absolutely 

 unintelligible and powerless unless in strict subordination 

 to natural selection. 



The reason why two writers of such extensive know- 

 ledge and undoubted ability have so completely failed in 

 dealing with the great problem of the modification of 

 organic forms, has been clearly indicated during the course 

 of this discussion. It has arisen from the fact that they 

 have devoted themselves too exclusively to one set of 

 factors, while overlooking others which are both more 

 general and more fundamental. These are, the enor- 

 mously rapid multiplication of all organisms during more 

 favourable periods, and the consequent weeding out of 

 all but the fittest in what must be on the whole stationary 

 populations. And, acting in combination with this anmoal 

 destruction of the less fit, is the 'periodical elimination 

 under recurrent unfavourable conditions, of such a large 

 proportion of each species as to leave only a small frac- 

 tion — the very elect of the elect — to continue the race. 

 It is only by keeping the tremendous severity of this in- 

 evitable and never-ceasing process of selection always 

 present to our minds, and applying it in detail to each 

 suggested new factor in the process of evolution, that we 

 shall be able to determine what part such factors can take 

 in the production of new species. It is because they have 

 not done this, that the two authors, whose works have 

 been here examined, have so completely failed to make 

 any real advance towards a more complete solution 

 of the problem of the Origin of Species than has been 

 reached by Darwin and his successors. 



