PREFACE 



1\ /TY object in writing this book is primarily to 

 call attention to some of the many questions 

 which are raised by an enquiry into the relative 

 antiquity of existing plants,- and to illustrate the 

 nature of the evidence afforded by the records of 

 the rocks. One may agree with the dictum, * There 

 is but one art — to omit/ but to practise this art is 

 often a difficult task. While fully conscious of the 

 incompleteness of the treatment of the subjects dealt 

 with in these pages, and of defects in the method of 

 presentation, I hope that I may succeed in attracting 

 some of my readers who are already interested in 

 living plants to the study of plants of former ages. 



I am greatly indebted to my colleague Dr C. E. 

 Moss for reading the proofs and for many valuable 



