vi CONTROLLED NATURAL SELECTION 



Theory of Sexual Selection. If therefore it 

 could be shown that the origin of secondary 

 sexual characters does not require this second 

 Theory for their explanation, and if at the 

 same time it can be shown that the origin 

 of these characters is precisely similar to that 

 of all characters : then the greater Theory, 

 instead of being weakened by the Theory of 

 Sexual Selection, will be strengthened by 

 this widening of its capacity. This is the 

 endeavour of the new Theory. 



It follows, therefore, that it has as a foun- 

 dation Darwin's Theory of the Origin of 

 Species, and thus it has support : but it is also 

 open to all the many arguments which are 

 levelled against this foundation. The Theory 

 does not deal only with secondary sexual 

 characters, but also with very many others 

 which cause di- or poly-morphisms. The 

 Theory is described as much as possible in 

 simple language ; technical words are when- 

 ever possible avoided, in order that it may 

 be intelligible to naturalists and field ob- 

 servers, for it is their valuable work which 

 is required for its substantiation or the re- 

 verse. New terminologies are not introduced, 

 although for descriptive purposes they would 

 have been invaluable, because on account of 



