478 
LUMBWA CAVES 
Eggs included in the above list, of whose taking I can find 
no previous printed record, are Francolinus mulemce, Lybius 
bidentatus cequatorialis, Lanius mackinnoni, Poliospiza 
angolensis somereni, Phyllastrephus albigularis, Chalcomitra 
angolensis, Cisticola lateralis. 
The 126 species here recorded constitute about one-fifth 
of the birds which in all probability breed within the limits 
of the Uganda Protectorate. 
LUMBWA CAVES 
An Investigation into Certain Mineral Deposits 
Obtained Therefrom 
By C. W. Hobley, C.M.G. 
Also Note by V. H. Kirkham and W. C. Birch 
Early in 1918, in response to an inquiry, the District 
Commissioner at Kericho sent down some specimens of a soft 
rock, which the natives excavate from caves in that district 
and use as food for their live-stock. 
The bulk of the specimens consisted of grey, powdery 
ash and a light volcanic tuff, and reminded one of certain 
rocks from other parts of the world. Chemical tests confirmed 
this, and one specimen yielded as much as 18 per cent, of 
tricalcic phosphate. This percentage compares badly with 
phosphate rocks in other parts of the world (but of quite 
different origin) which carry phosphate ; hut it was enough to 
warrant further investigation, and the region was accordingly 
visited by the Government Analyst and myself in March 1918, 
and specimens taken from each of the caves visited. 
We left Lumbwa, and marched to Kericho Government 
Station. The following day, leaving our caravan there, w T e 
first explored the Bagau Cave, which is about seven and a 
half miles to the north of the station. This cave occurs 
behind a small waterfall in the steep valley of a small stream 
which runs towards the Nyando River. The cave is of artificial 
origin, and made for the purpose of extracting a layer of soft 
rock which lies between two beds of lava. We penetrated 
