PREFACE 
THE general idea of this book, like that of others in the 
same series, such as “Electricity of To-day,” is to 
interest the reader in some at least of the many dis- 
coveries which have been achieved in our own times. 
It is especially open air botany, the story of the 
conquest of the world by green vegetation, that has 
interested me. This naturally leads to a consideration 
of the exquisite contrivances by which a plant suits 
itself to its position in the world. It is not in the least 
like a dead leaf blown hither and thither by every puff 
of wind, for it is a living creature able to respond to 
its friends and fittingly to answer its enemies. Plants 
do look after themselves in the eternal struggle for 
existence, 
The study of plant life reveals a strange mingling of 
benevolent co-operation with the most ruthless business 
competition which makes it always full of interest. 
The process of selecting what should be omitted has 
-been both difficult and delicate. Few people can have 
any just conception of the amount of printed matter in 
which the botany of to-day is contained. 
But one may roughly estimate the yearly output of 
the botanical world by an examination of that invaluable 
work, Just’s Botanische Jahres Berichte. This annual 
publication attempts to notice every important book, 
article and paper which has been published in one parti- 
cular year. It is not quite complete, for in spite of the 
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