PREFACE TO THE THIRD EDITION. 



IN the preparation of this edition so much has been added, 

 and so much modified, that to some extent the book may be cdn- 

 sidered as a new one. Nevertheless, the Editor has, as far as 

 possible, worked on the plan laid down by Prof. Henfrey, and ex- 

 plained by him in the following quotation from the original Preface. 

 Adverting to some remarks made by Sir Joseph Hooker and Dr. 

 Thomson to the effect that 



" disservice is done to the cause of Botany by occupying the attention 

 of students in the first instance with the abstract parts of the science," 



Prof. Henfrey remarks, in terms as applicable now as at the time 

 they were first written (1857), that 



" The largest class of students of Botany are those who pursue the 

 subject as one included in the prescribed course of medical education. 

 One short course. of Lectures is devoted to this science, and three months 

 is commonly all the time allotted to the teacher for laying the foundations 

 and building the superstructure of a knowledge of Botany in the minds of 

 his pupils, very few of whom come prepared even with the most rudimen- 

 tary acquaintance with the science. To direct the attention of the 

 student to a series of isolated facts and abstract propositions relating to 

 the elementary anatomy of plants, is to cause him to charge his memory 

 or his note-book with materials in which he can take but little interest, 

 from his incapacity to perceive their value or applications. Some of the 

 most important questions of Physiology are as yet in no very advanced 

 state, and the conflicting evidence on many of these cannot be properly 

 appreciated without an extensive knowledge of plants. 



