Vlll PREFACE. 



Mr Wethered of Cheltenham and others have assisted me in a 

 similar manner. I would also express my gratitude to Dr Hoyle 

 of Manchester, Mr Platnauer of York, and Mr Rowntree 

 of Scarborough for the loan of specimens. 



To Dr Henry Woodward of the British Museum I am 

 indebted for the loan of the woodblocks made use of in 

 figs. 10, 47, 60, 66, and 101, and to Messrs Macmillan for the 

 process-block of fig. 25. 



For the photographs reproduced in figs. 15, 34, 68, 102 

 and 103 I owe an acknowledgment to Mr Edwin Wilson of 

 Cambridge, and to my friend Mr C. A. Barber for the micro- 

 photograph made use of in fig. 40. 



In conclusion I wish more particularly to thank my wife, 

 who has drawn by far the greater number of the illustrations, 

 and has in many other ways assisted me in the preparation 

 of this Volume. 



In Volume II the Systematic treatment of Plants will 

 be concluded, and the last chapters will be devoted to such 

 subjects as geological floras, plants as rock-builders, fossil 

 plants and evolution, and other general questions connected 

 with Palaeobotany. 



A. C. SEWARD. 



BOT.^XIOAL LAB0R.4T0RY, CaUBRIDGE. 



March, 1898. 



