viii PREFACE 



I took advantage of the circumstances of my life to make, 

 between the years 1890 and 1896, a prolonged investigation of 

 the plants of the British flora, mainly from the standpoint of 

 dispersal by water. This involved the study of the seed-drift 

 of ponds and rivers and of the plants supplying it, a study 

 which brought me into close relation with aquatic and sub- 

 aquatic plants. This line of investigation led me into contact 

 with many other aspects of plant-life ; and as time went on 

 my field of interest extended to the plants of dry stations and 

 to the bird as an agent in plant-dispersal. Only a few of these 

 results have been published, as in the journals of the Linnean 

 Society and of the Royal Physical Society of Edinburgh as well as 

 in the pages of Science Gossip. They lie for the most part still 

 within my note-books, and fitly so, since I regarded such studies 

 chiefly as a preparation for the investigation of the general 

 question of plant-dispersal. 



When again, in October, 1896, I found myself once more in 

 the Pacific, the subject was taken up again with zeal ; but my 

 larger experience had only increased my diffidence, and the 

 unknown looked so overwhelming that I settled down for the 

 next three years content with merely making experiments and 

 recording observations. Here again the main problem was 

 attacked through the study of seed-buoyancy, and gradually 

 it led me to the systematic study of the mangroves and of the 

 beach-plants, whilst my inland excursions brought me into 

 familiarity with the plants of the interior. My geological 

 exploration of the island of Vanua Levu, in Fiji, greatly 

 assisted me by giving a method to my botanical examination 

 of the island. 



Whilst working out my geological collections in England, in 

 the years 1900-1902, I devoted an hour or two daily to the 

 elaboration of my botanical notes and to a consideration of 

 the problems concerned. During a winter in Sicily I took up 

 again the subject of the beach-plants ; and after the publica- 

 tion of the volume on the geology of Vanua Levu I was able 

 to accomplish a plan, for years in my dreams, of visiting the 

 eastern shores of the Pacific. During a period of three months 



