iv MODERN EVOLUTION 129 



February 1858, something led him to think of the 

 * positive checks ' described by Malthus in his Essay 

 on Population, a book which he had read some years 

 before. ; Oddly enough, therefore, the honours lie 

 with the maligned Haileybury Reverend Professor of 

 Political Economy in furnishing both Darwin and 

 Wallace with the clue. The * positive checks ' war, 

 disease, famine Wallace felt must act even more 

 effectively on the lower animals than on man, because 

 of their more rapid rate of multiplication. And he 

 tells us, in the prefatory note to a reprint of his paper, 

 1 there suddenly flashed on m^ ne idea of the sur- 

 vival of the fittest, and in the two hours that elapsed 

 before my ague fit was over I had thought out the 

 whole of the theory, and in the two succeeding even- 

 ings wrote it out in full and sent it by the next post 

 to Mr. Darwin,' asking him, if he thought well of the 

 essay, to send it to Lyell. ' This Darwin did with 

 the following remarks : ' Your words have come true 

 with a vengeance that I should be forestalled. . . . 

 I never saw a more striking coincidence ; if Wallace 

 had my MS. sketch written out in 1842, he could 

 not have made a better short abstract ! Even his 

 terms now stand as heads of my chapters. Please 

 return me the MS., which he does not say he wishes 

 me to publish ; but I shall, of course, at once write 

 and offer to send to any journal. So all my origin- 

 ality, whatever it may amount to, will be smashed, 

 though my book, if it will ever have any value, will 

 not be deteriorated, as all the labour consists in the 

 application of the theory.' Darwin came out well in 

 this business. For to have hit upon a theory which 

 interprets so large a question as the origin and causes 



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