VI PREFACE 



stages in the history of the earth. It is my intention to 

 complete Volume III with as little delay as possible. As I 

 have written elsewhere, the past history of the Flowering 

 plants needs special treatment, and anything more than a mere 

 compilation can be adequately attempted only after consider- 

 able research and with the assistance of botanists possessing 

 a special knowledge of different families of Angiosperms. The 

 need of a critical examination of available data in regard to 

 the geological history of this dominant group will not be lost 

 sight of. 



I am well aware that while certain genera have received 

 an undue share of attention in the present volume, others 

 have been ignored or treated with scant consideration. For 

 this inconsistency I have no excuse to offer, beyond the state- 

 ment that the subject is a large one, and selection is necessary 

 even though the work consists of three volumes. 



The publication in 1909 of a collection of excellent photo- 

 graphs of Palaeozoic Plants, with brief descriptive notes, by 

 Mr Newell Arber, as one of a series of popular " Nature Books," 

 bears striking testimony to the remarkable spread of interest 

 in the study of the vegetation of the past, which is one of the 

 outstanding features in the recent history of botanical science. 



In the list of illustrations I have mentioned the source of 

 all figures which have been previously published. I would, 

 however, supplement the statement of fact with an expression 

 of thanks to corporate bodies and to individuals who have 

 allowed me to make use of blocks, drawings, or photographs, 



I wish to thank my colleague, Mr A. G. Tansley, for placing 

 at my disposal several blocks originally published in the pages 

 of the New Phytologist. To Professor Bertrand of Lille and to 

 his son Dr Paul Bertrand I am indebted for several prints and 



