PREFACE. 



The " Flora of Tropical Africa " has met with many vicissitudes. It 

 was projected by Sir William Jackson Hooker as part of the series of 

 Colonial and Indian Floras to be produced at Kew which he initiated 

 The immediate impulse which led the Government to sanction the 

 undertaking was given by Dr. Livingstone on his return from the 

 Zambesi Expedition (1858-64), to which Dr. (afterwards Sir John) Kirk 

 had been attached as naturalist. The work having been offered to Dr. 

 Kirk and declined by him was entrusted in 18G4 to Sir Joseph Hooker 

 and Professor Oliver jointly, and was to be completed in four volumes. 



Sir Joseph Hooker succeeded to the Directorship of the Royal 

 Gardens in 18G5, and was in consequence obliged to resign the prepara- 

 tion of the Flora to Professor Oliver, although he contributed some share 

 to both volumes i. and ii. Professor Oliver further obtained the assist- 

 ance of other botanists. 



Vol. I. appeared in 1868, vol. ii. in 1871, and vol. iii. in 1877. 

 It was soon evident that the work would exceed the limits at first 

 assigned to it. Not less than five additional volumes will be now 

 required to enumerate completely and describe the known plants of 

 Tropical Africa. 



In the preface to the first volume Professor Oliver states that for 

 the geographical region to which he gave the name Lower Guinea he 

 was almost wholly dependent on the i^ngolan collections made at the 

 cost of the Portuguese Government in 1853-01 by Dr. Frederick 

 Welwitsch. 



This botanist, Professor Oliver adds, " has freely granted us the 

 opportunity of inspecting his collections, which, in respect of judicious 

 selection and admirable preservation, are without rival. His carefully 

 accurate notes upon the fresh plants have also been at our service. 

 Without the access to Dr. Welwitsch's Herbarium this region would 

 have been comparatively a blank in the present work." 



Dr. Welwitsch died in 1872, having bequeathed his Herbarium to 

 the British Museum. This led to prolonged litigation on the part ot 

 the Portuguese Government, ending in a compromise. But the 



