HEREDITY AND VARIATION 



to experimenting with peas. For some thirty-five 

 years his work was left unnoticed, but within the 

 last lustrum it has come into its own, his essential 

 discovery being now regarded by many, in Pro 

 fessor Bateson s words, 1 as &quot; one of the lasting tri 

 umphs of the human mind.&quot; 



Until the rediscoveries which have brought Men 

 del s work into recognition, the popular view was 

 simply this: like produces not exactly like; this 

 fortuitous difference between parent and child we 

 call variation; by the operation of natural selec 

 tion favorable variations are perpetuated, and 

 unfavorable ones die out; hence, the origin of 

 species subsidiary factors being ignored as non 

 existent by the school of Weismann, and as rel 

 atively unimportant by the majority of biol- j 

 ogists. 



But natural selection selects; it does not originate 

 or create. And all these decades past, while fully 

 discussing the consequences of variation, we have 

 ignored the fundamental question, simply accept 

 ing it as a mysterious fact hardly likely to repay 

 investigation. Now, let me attempt to show what 

 Mendel and his successors of this generation have 

 accomplished, premising that the facts --if not, 

 indeed, the interpretation of them are no longer 

 in dispute, and that they will be familiar to every 

 amateur student in a decade. How satisfactory 

 to the students of Herbert Spencer are these latest 



1 Presidential address to the section of zoology of the 

 British Association, Cambridge, 1904. 



117 



