viii I'REFACE 



Our two volumes contain practically all the matter 

 that it now seems desirable to publish. But at some 

 future time others may find interesting data in what 

 remains imprinted ; this is certainly true of a short 

 series of letters dealing with the Cirripedes, which 

 are omitted solely for want of space. 1 



We are fortunate in being permitted, by Sir 

 Joseph Hooker and by Mr. Wallace, to publish 

 certain letters from them to Mr. Darwin. We have 

 also been able to give a few letters from Sir Charles 

 Lyell, Hugh Falconer, Edward Forbes, Dr. Asa 

 Gray, Professor Hyatt, Fritz Miiller, Mr. Francis 

 Galton, and Sir T. Lauder Brunton. To the two 

 last named, also to Mrs. Lyell (the biographer of Sir 

 Charles), Mrs. Asa Gray and Mrs. Hyatt, we desire 

 to express our grateful acknowledgments. 



The present volumes have been prepared, so as to 

 give as full an idea as possible of the course of Mr. 

 Darwin's work. The volumes therefore necessarily 

 contain many letters of a highly technical character, but 

 none, we hope, which are not essentially interesting. 

 With a view to saving space, we have confined our- 

 selves to elucidating the letters by full annotations, 

 and have for the same reason — though with some 

 regret — omitted in most cases the beginnings and 

 endings of the letters. For the main facts of Mr. 

 Darwin's life, we refer our readers to the abstract of 

 his private Diary, given in the present volume. 



Mr. Darwin generally wrote his letters when he 

 was tired or hurried, and this often led to the omission 

 of words. We have usually inserted the articles, 



1 Those addressed to the late Albany Hancock have already appeared 

 in the Transactions of the Tyneside Nat. Field Club, VIIL, p. 250. 



