84 Variation 
natural selection is quite independent of the question, how the 
variations to be selected arise. They may arise slowly, from simple 
fluctuations, or suddenly, by mutations; in both cases natural 
selection will take hold of them, will multiply them if they are 
beneficial, and in the course of time accumulate them, so as to 
produce that great diversity of organic life, which we so highly 
admire. 
Darwin has left the decision of this difficult and obviously sub- 
ordinate point to his followers. But in his Pangenesis hypothesis 
he has given us the clue for a close study and ultimate elucidation 
of the subject under discussion. 
