PREFACE 



not unconscious of the difficulties met with in 

 laying all the questions mentioned above before a 

 wider circle of readers who have not devoted 

 themselves especially to physiological work in 

 biology. A fair knowledge of physics and chem- 

 istry, both organic and physical, is required 

 besides the great number of biological facts which 

 must be remembered when we try to obtain a 

 satisfactory survey of the general physiology of 

 the plant. It is therefore rather difficult to 

 present the subject of our book in a condensed 

 but clear and rather popular form, and I may 

 express my doubts as to whether it can be done 

 at the present day as perfectly as had been my 

 wish. 



So I must beg my readers to be indulgent if my 

 intentions have not been carried out as I would 

 have desired. At least no one will finish the book 

 without the feeling of satisfaction that Modern 

 Science is going to touch on problems so lofty 

 that before our days their solution could never 

 have been dreamed of. 



F. C. 



UNIVERSITY OF PRAGUE, 

 Junt> 1911. 



