Vlll PREFACE 



In spite of expressed opinions to the contrary, I am 

 convinced that much valuable exercise in observational 

 and descriptive science can be obtained by learning to 

 draw and properly describe the outline, margin, base 

 and apex, and other peculiarities of leaves ; and it is 

 after considerable experience and mature reflection that 

 I earnestly commend the advice in this connection I have 

 ventured to offer on p. 28. 



Some technical terms are indispensable ; but so they 

 are in carpentry, in a game of cricket, or in diplomacy ! 

 It is absurd to complain that the study of nature should 

 demand technical terms to shorten and give point to 

 description. It is only when such terms are multiplied 

 unnecessarily and pedantically that the student has 

 legitimate grounds for complaint: exact and new ideas 

 must have definite terms for adequate expression. 



As regards the illustrations, they are to a large 

 extent due to Miss Dawson, to each of whose drawings 

 the letter (I)) is appended. The beautiful prints of 

 leaf- venation are taken from Ettingshausen, denoted by 

 (Ett). Other illustrations are original, or their sources 

 are acknowledged as in Vol. I. 



I must record my thanks to Prof. I. Bayley Balfour 

 for specimens of Arctic and Alpine willows grown in 

 the Edinburgh Botanic Gardens ; to Mr F. F. Blackman 

 for revising the proofs of Chapters IX XII; and to 

 my wife and son for preparing the glossary and index. 



H. M. W. 



Cambridge, October 1904. 



