x INTRODUCTION 



at pp. 271-275 on the semi-parasites Euphrasia, 

 Melampyrum, Peiicularis, Bartsia, Lathrcea, and Viscum ; 

 and Chapter IX. on Weeds in Ponds and Water 

 Courses. To all those who so kindly responded to 

 the inquiry, the results of which are summarised in 

 Chapter VI., and who made many helpful suggestions, 

 I tender my warmest thanks, as also to many others, 

 both at home and abroad, who may not be mentioned 

 personally. In connection with the preparation of 

 Appendix IV., dealing with legislation enforcing the 

 destruction of weeds in various countries, I must 

 express much gratitude for the kind help received from 

 the Agents-General for the Colonies, and from foreign 

 departments of agriculture, as well as for information 

 received through the Colonial Office and Foreign Office 

 by the Board of Agriculture and Fisheries .and kindly 

 placed at my disposal. I am much indebted to the 

 artists who have contributed such excellent work for 

 the improvement of this volume, especially to my wife 

 (sketches initialled A. S. L.), to Miss B. Reid, Miss M. 

 Smith, and Mr. J. C. Varty-Smith, all of whom have 

 taken considerable pains to ensure good illustrations. 

 The blocks illustrating " Java " beans have been kindly 

 lent by the editor of The Field. For help in reading 

 the proofs, and in preparing the notes on legisla- 

 tion and the index, I am indebted to my colleague 

 Mr. ]. L. Bryan. 



I shall be most happy to receive criticisms and 

 suggestions for the improvement of any part of this 

 volume ; and as there are sure to be omissions, I shall 

 look out with a lively interest for the aid which readers 

 will be in a position to give. 



If this volume helps in but a small degree to 

 eliminate some of our weeds, the labour of preparing 

 it will not have been in vain. I hope the critics will 



