PREFACE TO FOURTH EDITION 



A textbook of any progressive Science needs to be revised from time 

 to time, if it is to serve the student as it should do. This book, fii 

 issued a quarter of a century ago, has been twice revised. In the pro- 

 duction of the Third Edition the author gratefully acknowledged 

 the help of Professor Drummond in respect of his new Chapter XXXV., 

 on Heredity and Variation, and of Dr. Bond in the general revision of 

 the parts dealing with Physiology. The exhaustion of that Edition 

 has given the opportunity for another general revision of the Text, 

 together with some additions of fresh matter. In producing this Fourth 

 Edition the author wishes to acknowledge the general help of Professor 

 Wardlaw, and in particular his revision of Chapters XXL to XX\ III. 

 Both Professor Wardlaw and myself have also made certain other 

 additions, as required. The result of these changes has been to 



modernise the Text. 



F. O. BOWER. 



PREFACE TO THIRD EDITION 



The present Volume was framed in 1919 upon the Courses of Elemen- 

 tary Lectures on Botany given in Glasgow University during a h 

 succession of years. Those Courses were progressively re-modelled 

 and developed as time went on, while the clastic limits of a book 

 have allowed the introduction of sundry additions. And so in 

 successive issues the text has expanded. But the main oh 

 throughout has been in the first place that of presenting the individual 

 plant as a living, growing, self-nourishing, self-adapting creature, 1 

 I always endeavoured to sketch it in the Lecture Room, and to dt 

 monstrate it in the Laboratory. 



The subject-matter is parcelled out into a series of E: 

 one self-contained. They arc designed so as to fii together and ton 



vi 1 



