456 Charles Darwin. 



tion by Darwin himself of a letter from Mr. Wallace, inclosing 

 a brief and strikingly similar essay on the same subject, entitled 

 " On the Tendency of Varieties to depart indefinitely from the 

 Original Type." Mr. Darwin's action upon the reception of 

 this rival essay was characteristic. His own work was not yet 

 ready, and the fact that it had been for years in preparation 

 was known only to the persons above mentioned. He proposed 

 to have the paper of Mr. Wallace (who was then in the 

 Moluccas) published at once, in anticipation of his own leis- 

 urely preparing volume; and it was only under the solicitation 

 of his friends cognizant of the case that his own early sketch 

 and the corroboratory letter were printed along with it. 



The precursory essays of Darwin and Wallace, published in 

 the Proceedings of a scientific society, can hardly have been 

 read except by ;i narrow circle of naturalists. Most thoughtful 

 investigating naturalists were then in a measure prepared for 

 them. But toward the close of the following year (in the 

 autumn of 1859) appeared the volume " On the Origin of 

 Species by means of Natural Selection, or the Preservation of 

 Favored Races in the Struggle for Life," the first and most 

 notable of that series of duodecimos which have been read and 

 discussed in almost every cultured language, and which within 

 the lifetime of their author have changed the face and in some 

 respect the character of natural history, — indeed have almost 

 as deeply affected many other lines of investigation and 

 thought. 



In this Academy, where the rise and progress of Darwinian 

 evolution have been attentively marked and its bearings criti- 

 cally discussed, and at this date, when the derivative origin of 

 animal and vegetable species is the accepted belief of all of us 

 who study them, it would be superfluous to give any explana- 

 tory account of these now familiar writings ; nor, indeed, would 

 the pages which we arc accustomed to consecrate to the memory 

 of our recently deceased Associates allow of it. Let us note in 

 passing that the succeeding volumes of the series may be 

 ranked in two classes, one of which is much more widely 

 known than the other. One class is of those which follow up 

 the argument for the origination of species through descent 

 with modification, or which widen its base and illustrate the 



