PREFACE 



The general idea of this book, like that of others in the 

 same series, such as u 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 BotaniscJie 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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