Vi PREFACE. 



describe as comprehensively as possible the important caoutchouc- 

 containing and medicinal plants which the order includes in Tropical 

 Africa. 



I must again record my acknowledgments of the assistance given 

 me by Mr. C. H. Wright in preparing the manuscript for the press and 

 in checking the proofs, and to Mr. N. E. Brown for working out the 

 geographical distribution. 



For the detailed topography the third edition of the " Spezial- 

 Karte von Afrika," Gotha : Julius Perthes, 1893, has been chiefly 



used. 



W. T. T.-D. 



Kew, February 1902. 



