vi PREFACE 



some who use this book wish to use it in connection with 

 floras now long published, and also that it is impossible to 

 reset such a book all through for each edition, so that it is 

 necessary to insert a little "padding" on practically every 

 page. 



Ecological, morphological, and other subjects have been 

 dealt with by giving comparatively full accounts under se- 

 lected genera. By referring, first to the subject, e.g. to 

 Adventitious Buds, and then to the genera mentioned there, 

 e.g. Begonia, Bryophyllum, &c., a fairly detailed account of 

 each subject may be put together. In using the book, the 

 subjects mentioned under a genus should always be looked up, 

 to find other examples, e.g. under Aesculus look up Bud, Leaf, 

 Leaf-mosaic, Cincinnus, Dichogamy, Change of Colour, >S:c. 

 A book like this must obviously be a compilation, and 

 I have to express my warmest thanks to Prof. A. Engler for 

 permission to draw upon the vast mass of material con- 

 tained in Die Natiirlichen Pflanzenfamilien. Owing to the 

 war I have had no opportunity of asking him to renew this 

 permission, and I trust that he will understand as much. 

 When an article, as is frequently the case with the grouping 

 of the sub-families within the family, is taken from the work 

 mentioned, I have acknowledged the same by giving the 

 name of the author. Otherwise I have in general: drawn 

 upon the book for the genera accepted by its authors, for 

 the number of species (which has been brought roughly up 

 to date by aid of the Supplements to the Index Kewensis), 

 and for their geographical distribution. 



The list of friends to whom I owe valuable suggestions, 

 useful pieces of assistance, and the like, is very long, and I 

 have no doubt that the following enumeration is incomplete, 

 and must ask the pardon of those who do not figure in it, 

 through some oversight on my part to note down their 

 names at the moment the help was given. In the first place 



