8 PREFACE. 



authors, could not have been undertaken, had it n< 

 been for the liberality of the Lords Commissioners 

 Her Majesty's Treasury, who through the representation 

 of the Right Honourable the Chancellor ot the Exchequei 

 have been pleased to grant a sum of one thousand pounc' 

 towards defraying part of the expenses of publication. 



I have myself published separate volumes on the ** Stru( 

 ture and Distribution of Coral Reefs;" on the "VolcanJ 

 Islands visited during the Voyage of the Beagle 

 and a third volume will soon appear on the "Geolo^ 

 of South America." The sixth volume of the **Ge< 

 logical Transactions " contains two papers of mine oj 

 the Erratic Boulders and Volcanic Phenomena of Soutj 

 America. Messrs. Waterhouse, Walker, Newman, an^ 

 White have published several able papers on the Insect^ 

 which were collected, and I trust that many others will 

 hereafter follow. The plants from the southern parts of 

 America will be given by Dr. J. Hooker, in his great work 

 on the Botany of the Southern Hemisphere. The Flora 

 of the Galapagos Archipelago is the subject of a separate 

 memoir by him, in the " Linnean Transactions." The 

 Reverend Professor Henslow has published a list of 

 the plants collected by me at the Keeling Islands ; 

 and the Reverend J. M. Berkeley has described my 

 cryptogamic plants. 



I shall have the pleasure of acknowledging the great 

 assistance which I have received from several other 

 naturalists In the course of this and my other works ; but 

 I must be here allowed to return my most sincere thanks 

 to the Reverend Professor Henslow, who, when I was an 

 under-graduate at Cambridge, was one chief means of 

 giving me a taste for Natural History, who, during my 

 absence, took charge of the collections I sent home, and 

 by his correspondence directed my endeavours, and who, 

 since my return, has constantly rendered me every assistance 

 which the kindest friend could offer. 



June, 1845. 



