VI 



PREFACE 



for much help which he very generously gave me. 

 The task of harvesting and recording the peas, on 

 the scale on which the experiment is now carried on, 

 is made possible, and pleasant, by the assistance of 

 Mr. Frank Sherlock ; whilst the fullness of the harvest 

 itself is due to the energy and skill of my gardener, 

 iMr. George Reeves, 



NOTE TO SECOND EDITION 



The issue of a Second Edition gives me oppor- 

 tunity to correct a few mistakes due to my own 

 inadvertence. For discovering and pointing out to 

 me these mistakes I am especially grateful to 

 my cousin. Dr. 0. V. Darbishire, and to my 

 friend Mr. C. F. Meade. 



A. D. D. 



