vill PREFACE. 
H. Courtet, Dr. A. Engler, Dr. J. W.C. Goethart, Dr. J. A. Henriques, 
Professor H. Lecomte, Dr. C. A. M. Lindman, Dr. C. H. Ostenfeld, 
Professor R. Pirotta, Dr. A. B. Rendle, Professor Hans Schinz, Professor 
EK. Warming, Dr. R. Wettstein, Dr. E. De Wildeman, and Dr. A. 
Zahlbruckner, for the generous loan of type specimens and other mate- 
rial from the herbaria under their charge. 
I must add my final acknowledgments of the aid given me by 
Assistants in the Herbarium of the Royal Botanic Gardens; to Mr. 
C. H. Wright, A.L,S., in preparing the manuscript for the press and in 
checking the proofs; andto Mr. N. E. Brown, A.L.S., for working out 
the geographical distribution. 
For the detailed topography the third edition of the “ Spezial-Karte 
von Africa” (Gotha: Justus Perthes, 1893) has been chiefly used. 
Wee, 1): 
WITCOMBE ; February 17, 1913. 
