X PREFACE 



technical terms applied to the Higher Plants, including 

 those used or mentioned in this volume. 



In the preparation of this volume I have, in 

 addition to new and original observations, drawn 

 freely on many sources of information, which are too 

 numerous to permit of specific mention. I would, 

 however, record my indebtedness to the w^orks 

 of Kerner, Christ, and Schroeter, mentioned in 

 Appendix III. ; to various scientific memoirs by 

 Professor Bonnier and other members of the French 

 School of Experimental Alpine Cultivation ; and to 

 those of the Swiss School of Ecology, of which 

 Professor Schroeter of Zurich is the head. 



I am also indebted to many friends for information, 

 advice, and criticism. To my wife I owe many 

 thanks for the drawings of the text- figures, which are 

 original, except where the contrary is stated in each 

 case, and also for much help in many other directions, 

 including the reading of the proof-sheets. To my 

 friend Mr John Parkin, M.A., of Trinity College, I 

 would express my thanks for much information, and 

 for the value of his co-operation in field work in 

 Switzerland. 



The photographs, which illustrate the letterpress, 

 were all taken in Switzerland during the past four 

 years, expressly for this work. In a majority of 

 cases the plants were photographed in situ, and the 

 prints and negatives are "untouched." For the 

 larger number I must plead responsibility, but I am 

 greatly indebted to my friend Major George Dixon 



