viii PREFACE 



Lastly, I wish to express my thanks to Professor Pritchard 

 of the Royal Agricultural College, Cirencester, for having 

 read through all my manuscripts (except Chapters I. and 

 XII.), and for the many valuable suggestions which he has 

 offered to me in connection with this work. 



And I thank M. Johannes Rafn, Seed Merchant, of 

 Copenhagen, for much valuable information with regard to 

 tree seeds and their germinative capacity. 



PERCIVAL T. MAW. 



NUTFIELD, SURREY, 



i st January 1909. 



