THE 



VOYAGE OF H.M.S. CHALLENGER. 



BOTANY. 



REPORT on Present State of Knowledge of various Insular Floras, 

 being an Introduction to the Botany of the Challenger Expedition. 

 By William Botting Hemsley, A.L.S. 



PRELIMINARY REMARKS. 



In the Introductory Notes on the vegetation of the various islands included in the Reports 

 on the Botany of the Expedition, are embodied tables showing the distribution of the 

 genera and species of each island or group of islands. There are also observations on the 

 composition, affinities, &c, of the different insular floras, together with references to the 

 diverse agencies operating in the dispersal of plants, whilst numerous facts and suggestions 

 bearing upon the same subject are scattered throughout the lists. Finally, the Appendix 

 to the third Part of the Botany is devoted to the record of evidence of the part played by 

 oceanic currents and birds in the transport of seeds from place to place. 



This General Introduction is not limited to a mere summary of the facts contained in 

 the Reports, and speculations thereon ; it has been so extended as to form an epitome of the 

 Botany of a large number of Oceanic Islands, and of the Antarctic Regions generally. The 

 special characteristics of Insular Vegetation in various parts of the world are set forth and 

 compared with continental vegetation ; and, as a whole, the work may perhaps serve as 

 an indication to travellers of the nature and extent of the observations required for the 

 advancement of this most interesting subject. 



LITERATURE RELATING TO INSULAR FLORAS. 



A list of works devoted to, or bearing upon this subject, is given at the end of this 

 Introduction ; but it seems desirable to say a few words respecting the teachings of a few 

 travellers and authors who have specially investigated or promoted the philosophical 



(BOT. CHALL. EXP. — INTRODUCTION — 1885.) 1 



