30 
he subsequent history of the undertaking is conveniently 
summarised in the following extract from the preface to the 
mereath volume, by Sir William Thiselton-Dyer (August, 1898) :— 
“The Flora of Tropical Africa ae one with many vicissitudes. 
The immediate impulse which le e Government to sanction 
g was given by 
the Zambesi Expedition (1858-64), to which Dr. (afterwards 
Sir John) es had been attached as ‘naturalist. The work having 
been offered to Dr. Kirk and declined by him, was entrusted, 
in 1864, to Sir ‘Joseph Hooker onan ‘aepige Oliver jointly, and 
Gardens in ie nd was, in consequence, ee to resign wie 
pr vices f the Flora to Professor Oliver, although he con- 
ae share to both volumes I. and II. Professor Oliver 
fuither obtained the assistance of other Hotaniéts. 
Vol. I appeared in 1868, Vol. II in L871, and Vol. IIL 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 er 
Guinea, he was Seon oe dependent on the Angolian col- 
lections made the cost of the Portuguese Government, in 
1853-61, by Dr. Frederick Welwit tsch. 
This  botani ist, Professor Oliver adds, ‘has ie granted ~ the 
p in 
up : 
at our service. Without the access to Dr. Welwitsch’s Herbarium 
pair region would have been conapecntively a blank in the present 
ork.’ 
pes Welwitsch died in 1872, having bequeathed his Herbarium 
to the British Museum. This led to aoe litigation on the 
part of the Portuguese peveainnala, ending in a compromise, 
but the collections were no longer siuilsble for study at Kew, 
and Professor Oliver biter pacar abandoned the further prosecu- 
tion of the work. He retired from kis official post in 1890. 
Meanwhile the publication of the first three volumes had con- 
nar geal bipap oaoth botanical research in Africa. Sir John Kirk 
me 
. 
had l-General at Zanzibar, and lost no pies’ 
of encouraging collectors. Sir H. H. Johnston, K.C.B., 
Commissioner in British Central Africa, imitated his exampl 
e in 
British Central Africa. Much valuable work in Equatorial eo 
o done by the missionaries of the Church Missionary 
Society The Temperate Flora discovered on Kilimanjaro by the 
Rev. . ‘Ne ew, who was probably the first human being to reach 
its snow-line, and the collections subsequently made by Mr. 
Joseph Thomson on the mountains of East ‘Equatorial Africa 
confirmed the relationships ‘of the high-level floras of Tropical 
Africa with those of the northern hemisphere on es one “hand 
and of the Cape on the other, which were first indicated by 
Mr. Mann’s collections on the Cameroons. These relationships 
