EDITOR'S PREFACE 



IN seeing the present volume through the press I have 

 reduced changes from the original to a minimum. 

 Of the trivial verbal alterations, inevitable in revision, no 

 special indication is supplied in the Text, but I have 

 found it necessary to make a few alterations and additions 

 that are denoted by enclosure within square brackets. 



In regard to the subject matter of this volume it may 

 be remarked that Chapter VII., should not be regarded 

 as giving a strictly defined histological account of Bark. 

 The Appendix, dealing with Seedlings, though evidently 

 not in the final state to which the Author intended to 

 bring it, is yet sufficiently complete to be of great use to 

 students, and more especially so thanks to the excellent 

 drawings made by Miss E. Dale from actual seedlings. 



A number of the illustrations (unsigned) are from 

 drawings made by the Author. Others obtained from 

 various botanical works are acknowledged as in the pre- 

 ceding volumes. Those marked " Irv " are from photo- 

 graphs made by Mr Henry Irving; of these, eight have 

 been previously published in my book Trees and their 

 Life Histories. While the illustrations initialled " E. D." 

 are from drawings by Miss E. Dale, who has been good 

 enough to calculate the respective scales of magnification 

 or reduction. 



As in the case of preceding volumes, Mrs Marshall Ward 

 is responsible for the preparation of the Index. 



PERCY GROOM. 



IMPERIAL COLLEGE, 

 SOUTH KENSINGTON. 

 March, 1909. 



