PREFACE Vii 
of considerable use, and the Principal (Sir Oliver Lodge) most 
kindly obtained for me a grant towards the cost of preparing 
the illustrations. By the courtesy of Dr A. B. Rendle, Keeper 
of the Botanical Department of the British Museum, and that 
of the Director of Kew Gardens, the Herbaria at those insti- 
tutions have been consulted and much useful information has 
been derived therefrom. Thanks are also due, and are hereby 
gratefully tendered, to Herr H. Sydow (of Berlin) and Mr J. 
Ramsbottom (of the British Museum) who have both given 
unstinted help, to Mr T. B. Roe (a very successful collector 
of specimens), Professor A. H. R. Buller, Mr A. D. Cotton 
Mr H. J. Wheldon, Mr C. Crossland, Mr J. Adams, Sir Frederick 
Moore, and many others in a smaller degree. 
W. B. GROVE. 
THE BotanicaL LAporatory, 
Usiversity oF BirnmincHay. 
July, 1913. 
