PREFACE ix 



Though in a few instances the grains have been converted 

 into grammes, the use of percentages in stating the results 

 in the great majority of cases will enable the reader to be 

 largely independent of the unit of weight employed. 



My original plan was to include in this volume the results 

 of my observations on the distribution of seeds by currents in 

 the West Indian region, and through the agency of the Gulf 

 Stream drift. However, this idea has been abandoned for at 

 least two reasons. In the first place, such materials would have 

 greatly added to the size of a book already large ; and, in the 

 second place, since the subject was concerned with quite 

 another matter, it could very well be treated in a separate 

 volume. Though much of the work done in this direction 

 has been put into shape, it has been decided to defer its 

 publication ; and in the meantime I hope to considerably add 

 to my facts relating to the occurrence of West Indian seed-drift 

 on the Atlantic shores of Europe. This is the continuation of 

 a study commenced by me in the Pacific about thirty years 

 ago, and taken up from time to time in diflFerent parts of the 

 tropics, many of the results being given in my book on Plant- 

 Dispersal (1906), and in various papers enumerated in the list 

 given on page xiii of that work. 



I would take this opportunity to ask any reader who is inter- 

 ested in the occurrence of West Indian seeds on the west coast 

 of Europe or on the neighbouring islands to communicate 

 with me. Having studied the question during four winters in 

 the home of the drift, in different parts of the West Indies, I 

 wish to make as complete as possible the materials relating to 

 this side of the Atlantic. These seeds are frequently stranded 

 on the beaches of Europe, between the North Cape and the 

 Straits of Gibraltar. Residents on the west coasts of Scandi- 

 navia, Scotland, Ireland, England (south-west), France, Spain, 

 and Portugal, and on the ofF-lying island groups, must often 

 come upon these stranded seeds. The great majority of the 

 seeds thus picked up do not come into the hands of any 

 person who has studied the subject. Some of those who read 



