6 
PREFACE. 
and winter aspects of the principal species. Supplementary 
photographs are given, in many cases, of the bole, which exhibit 
the character of the bark, and should prove a valuable aid in 
the identification of species. Others show in larger detail the 
flowers or fruit, and the characteristic leaf-buds in spring. 
The figures in the text have all been expressly drawn for the 
work with a view to showing at a glance the general character 
of the foliage, and in most cases the flower and fruit. 
The work is divided into two sections. Part I. including 
those species that are generally considered to be indigenous 
to the British Islands, with briefer notices of the introduced 
species that are closely related to them. Part II. being devoted 
to those of foreign origin, some of them introduced so long ago 
that they are commonly regarded as native by those who are 
not botanists. 
