NATURAL SELECTION 



ing for the illustration it gives of the habits of 

 a truly scientific mind. On his return to Eng- 

 land, in 1837, Mr. Darwin began patiently to 

 collect all kinds of facts which might be of 

 use in the solution of the problem, — " How is 

 organic evolution caused ? " It was only after 

 seven years of unremitting labour that he went 

 so far as to commit to manuscript a brief sketch 

 of his general conclusions, of which the main 

 points were communicated to his friends Sir 

 Charles Lyell and Dr. Hooker. A less wise and 

 sober speculator than Mr. Darwin would now 

 at once have rushed into print. A thinker less 

 thoroughly imbued with the true scientific spirit 

 would probably have suffered from not publish- 

 ing his views, and profiting by the adverse crit- 

 icisms of contemporary observers. It is a strik- 

 ing illustration of Mr. Darwin's patience and 

 self-restraint that he continued fifteen years 

 longer to work assiduously in testing the weak 

 and strong points of his theory, before present- 

 ing it to the public. And it is an equally inter- 

 esting illustration of his thoroughly scientific 

 temperament that, after so many years of soli- 

 tary labour, he should have been so little carried 

 away by the fascinations of his own hypothesis 

 as to foresee clearly all the more valid objections 

 which might be urged against it. After a care- 

 ful perusal of the recent literature of the sub- 

 ject, and especially of the skilful work of Mr. 



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