vi INTRODUCTION. 



in the same year he wrote to Mr. Wallace, " I infinitely admire 

 and honour your zeal and courage in the good cause of 

 Natural Science." 



In February 1858 Mr. Wallace wrote an essay at Ternate, 

 " On the Tendency of Varieties to depart indefinitely from the 

 original Type," which proved to be the proximate cause of 

 the publication of Mr. Darwin's "Origin of Species." The 

 manuscript of this paper was sent to Mr. Darwin, and reached 

 him on June 18th, 1858, and the views it expressed coincided 

 remarkably with those developed in Mr. Darwin's mind by 

 many different lines of investigation. He proposed to get Mr. 

 Wallace's consent to publish it as soon as possible ; but on the 

 urgent persuasion of Sir Joseph Hooker and Sir Charles Lyell, 

 a joint communication of some extracts from a manuscript 

 written by Mr. Darwin in 1839 1 844, and a letter written by 

 him to Professor Asa Gray of Boston, U.S., in 1857, together 

 with Mr. Wallace's paper, was made to the Linnean Society on 

 July 1st, 1858. As Sir Joseph Hooker wrote, "The interest 

 excited was intense, but the subject was too novel and too 

 ominous for the old school to enter the lists before armouring ; " 

 and there was no attempt at discussion. The further history 

 of the " Origin of Species " controversy is well known, and has 

 previously been sketched in the first volume of this library. 

 What deserves repeating and emphasizing is that Mr. Wallace 

 must rank as a completely independent and original discoverer 

 of the essential feature of the " Origin of Species." Mr. Wallace 

 originally termed his view one of progression and continued 

 divergence. " This progression," he wrote in the Linnean essay, 

 "by minute steps, in various directions, but always checked 

 and balanced by the necessary conditions, subject to which 

 alone existence can be preserved, may, it is believed, be followed 

 out so as to agree with 'all the phenomena presented by 

 organized beings, their extinction and succession in past ages, 

 and all the extraordinary modifications of form, instinct, and 

 habits which they exhibit." Nothing in scientific history is 

 more interesting or more admirable than the way in which 

 the two great discoverers in biological evolution fully admired 

 and recognized each other's independent work ; and continued 

 their intercourse through life untinged by any shadow of un- 

 worthy feeling. Mr. Darwin wrote to Mr Wallace on January 

 25th, 1859, "Most cordially do I wish you health and entire 



