VI PREFACE 



All the drawings in the work are original, and with the excep- 

 tion of the diagrammatic figures have be-en made by the author 

 from living or natural examples. The panicles or ' ears ' of the 

 grasses are all drawn the natural size of average specimens, 

 in order that the figures may be of use in the identification 

 of these important plants. 



The farm seeds are also drawn to a uniform scale ; their rela- 

 tive sizes may therefore be seen at a glance. 



In this as in all scientific study, practical work is absolutely 

 essential to a proper understanding of the subject ; in recognition 

 of the importance of such work I have introduced into the text 

 of the volume a series of exercises and experiments, illustrative 

 of the principles and facts to be studied. These and others, 

 which will suggest themselves to intelligent students, should be 

 attacked and carried out in the spirit of research, so that students 

 may learn to observe, record and discover things themselves. 



In conclusion, I tender my sincere thanks to my colleague 

 Mr Cousins, and also to Mr W. H. Hammond, Milton Chapel, 

 Canterbury, and Dr A. B. Rendle, of the British Museum 

 (Natural History Department), for valuable criticism and assist- 

 ance in reading through the proofs. 



JOHN PERCIVAL. 



South-Eastern Agricultural College, 

 Wye, Kent. 

 March, 1900. 



PREFACE TO THE SECOND EDITION 



The very appreciative reception and rapid sale of the first edition 

 have proved that a real want has been met by the book. 



The present edition has been emended and revised throughout 

 in accordance with recent work and the criticisms of botanical 

 friends. , 



I shall be grateful for any further suggestions which may be 

 deemed necessary to render the work more complete for educa- 

 tional purposes or more useful to the student of this and allied 

 branches of applied botany. 



JOHN PERCIVAL. 



Nov. 1 90 1. 



