iv PREFACE. 
sedentary at home, or locomotive only to the range of 
a single-day journey to and fro. Books and the manu- 
script communications of botanical friends have been 
largely resorted to, in order to extend and supplement 
the knowledge acquired by personal investigation. His 
writings are thus to be looked upon as a combination 
between actual observation at first-hand and rather 
elaborate compilation at second-hand. 
This present volume may be taken as a condensed 
summary from thousands upon thousands of individual 
facts, real or alleged, actually ascertained or accepted 
on faith. It is not to be expected that such a sum- 
mary has been made without errors and oversights on 
the part of the Author himself, besides those which 
may have been taken on trust from other writers or 
communicators. The attempted elimination of old 
errors, over and over again repeated in books, and of 
the many others of more recent date continually in- 
creasing their numbers, has been found one of the 
most unsatisfactory among the emendatory tasks under- 
taken. 
On the whole, however, it is believed that the present 
Compendium may be accepted by the botanists of 
Britain, as a fairly reliable exposition of that depart- 
ment of botanical science to which it relates. If so 
accepted, it may claim to constitute a new and advanced 
starting ground for further investigations. At any rate, 
the Author must himself feel well assured that his own 
past efforts would have been very greatly assisted, if 
he could have found any similar book forty years ago. 
For want thereof he has been compelled to sacrifice 
much time and labour in the accumulation of small 
facts, to be methodically arranged and then selected 
