38 A STUDY IN HEREDITY 



Natural Selection was alleged as a cause of 

 evolution by Darwin. Thereupon critics raised 

 objections. First they declared there had been no 

 evolution. Next they said there was no such thing 

 as Natural Selection. Nature, according to them, 

 worked in an altogether haphazard way. The 

 fittest did not survive. This view found especial 

 favour in the eyes of two aristocratic and orthodox 

 amateurs, the late Duke of Argyle and the present 

 Marquis of Salisbury, politicians, whose cabinet 

 rank gave weight to their opinions on matters 

 biological. Some professional biologists agreed 

 with, or followed, them. Thereupon experiments 

 to prove or disprove the actuality of evolution were 

 set a-going. Professor Wheldon has lately done to 

 death many crabs ; Professor Poulton has caused 

 the elimination of many chrysalises. They sought 

 for evidence of Natural Selection ! Under the eyes 

 of Cabinet Ministers and Professors alike, touching 

 perhaps their nearest and dearest, worked those 

 great causes of Natural Selection, those great agents 

 of the elimination of the unfittest, the various 

 zymotic diseases. They sought for evidence of 

 evolution ! Zymotic diseases have produced evolu- 

 tion of such vast political and biological importance 

 that the effects of all wars and all diplomacy fall 

 into insignificance beside it. 



Malaria and other saprophytic diseases, but 



