Origin of Species

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Distinction between the sterility of first crosses and of hybrids Sterility various in degree, not universal, affected by close in terbreeding, removed by domestication - Laws governing the sterility of hybrids - Sterility not a special endowment, but incidental on other difierences, not accumulated by natural se ...