Darwin- Wallace Celebration. 



On the Tendency of Species to form Varieties ; and on the 

 Perpetuation of Varieties and Species by Natural Means 

 of Selection. By CHARLES DARWIN, Esq., F.B.S., 

 F.L.S., & F.G.S., and ALFRED WALLACE, Esq. Com- 

 municated by Sir CHARLES LYELL, F.R.S., F.L.S., and 

 J. D. HOOKER, Esq., M.D., V.P.R.S., F.L.S., &c. 



[Read July 1st, 1858. J 



London, June 30th, 1858. 



MY DEAR SIR, The accompanying papers, which we have 

 the honour of communicating to the Linnean Society, and 

 which all relate to the same subject, viz. the Laws which 

 affect the Production of Varieties, Races, and Species, contain 

 the results of the investigations of two indefatigable natu- 

 ralists, Mr. Charles Darwin and Mr. Alfred Wallace. 



These gentlemen having, independently and unknown to 

 one another, conceived the same very ingenious theory to- 

 account for the appearance and perpetuation of varieties and 

 of specific forms on our planet, may both fairly claim the 

 merit of being original thinkers in this important line of 

 inquiry ; but neither of them having published his views, 

 though Mr. Darwin has for many years past been repeatedly 

 urged by us to do so, and both authors having now un- 

 reservedly placed their papers in our hands, we think it would 

 best promote the interests of science that a selection from 

 them should be laid before the Linnean Society. 



Taken in the order of their dates, they consist of : 



1. Extracts from a MS. work on Species *, by Mr. Darwin,. 



which was sketched in 1839, and copied in 1844, when the 



copy was read by Dr. Hooker, and its contents afterwards 



communicated to Sir Charles Lyell. The first Part is devoted 



* This MS. work was never intended for publication, and therefore was- 

 not written with care. C. D. 1858. 



