CHAPTER XIII. 



June 18, 1858, to November, 1859. 



[THE letters given in the present chapter tell their story 

 with sufficient clearness, and need but a few words of expla- 

 nation. Mr. Wallace's Essay, referred to in the first letter, 

 bore' the sub-title, 'On the Tendency of Varieties to depart 

 indefinitely from the Original Type,' and was published in the 

 Linnean Society's Journal (1858, vol. iii. p. 53) as part of the 

 joint paper of "Messrs. C. Darwin and A. Wallace," of which 

 the full title was ' On the Tendency of Species to form Varie- 

 ties ; and on the Perpetuation of Varieties and Species by 

 Natural Means of Selection.' 



My father's contribution to the paper consisted of (i) Ex- 

 tracts from the sketch of 1844 ' ( 2 ) P ar t f a letter addressed 

 to Dr. Asa Gray, dated September 5, 1857, and which is 

 given at p. 120. The paper was "communicated" to the 

 Society by Sir Charles Lyell and Sir Joseph Hooker, in whose 

 prefatory letter, a clear account of the circumstances of the 

 case is given. 



Referring to Mr. Wallace's Essay, they wrote : 



" So highly did Mr. Darwin appreciate the value of the 

 views therein set forth, that he proposed, in a letter to Sir 

 Charles Lyell, to obtain Mr. Wallace's consent to allow the 

 Essay to be published as soon as possible. Of this step we 

 highly approved, provided Mr. Darwin did not withold from 

 the public, as he was strongly inclined to do (in favour of 

 Mr. Wallace), the memoir which he had himself written on 

 the same subject, and which, as before stated, one of us had 



