526 DTI. J. W. GBEG0KY OS THE [Nov. 1 894, 



This shows that in each case the glacier with the larger collecting- 

 area goes the lower and farther below the neve-line. The distance 

 to which this 2000-feet addition to the height of Kenya would carry 

 down the glaciers cannot be determined ; it would depend (1) on the 

 rate of the motion of the glaciers, which is probably high — owing to 

 the steepness of the gradient and the enormous diurnal range of 

 temperature : I had intended to measure this, but the refusal of my 

 men to approach the snow-line rendered it impossible to do so ; and 

 (2) on the rate of ablation, which would probably be very great and 

 would lessen the length of the glaciers. 



The fact, moreover, that the valleys are glaciated to their bottoms 

 and that perched blocks still surmount the crests show that there 

 has been no very great denudation in the alpine zone since the 

 maximum glaciation. Thus, though there may have been a consider- 

 able lowering of the central plug which now forms the summit since 

 the time of maximum glaciation, in the later stages, as when the 

 glaciers were depositing the terminal moraines of the Teleki Valley, 

 the entire crater-walls had disappeared. Therefore, though the 

 lowering of the summit by denudation has no doubt helped to restrict 

 the downward extension of the glaciers, as these were more extensive 

 in times later than the destruction of the crater, this factor can 

 account for only a fraction of the balance of 3400 feet. 



In spite, however, of the absence of evidence of earth-movements 

 on the coast or of a glaciation of Kilinm Njaro, there is one line of 

 argument which shows that the elevation was not limited absolutely 

 to the Kenya district. On the higher summits of Kilima Njaro, 

 liuwenzori, Elgon, the mountains of Abyssinia and the Cameroons, 

 there is an alpine flora quite unlike anything in the lower country 

 of Equatorial Africa. This must once have extended across the 

 lower plateaux and retreated to the mountains as the land subsided 

 to a warmer and lower level. In the ' Geographical Journal ' l is 

 a map illustrating the present and former distribution of this alpine 

 flora, showing that a downward extension of the glaciers for a 

 little over 5000 feet would enable this distribution to be effected 

 without the intervention of any universal African ice age, and merely 

 as a result of its greater elevation. The fact that the fauna extended 

 to the Cameroons is of interest, as the submerged fiord beyond the 

 mouth of the Congo shows that great subsidence has occurred in 

 that region. 2 



1 J. W. Gregory, ' Contributions to the Physical Geography of British East 

 Africa,' 1894, vol. iv. p. 289. 



2 Enrico Stassano, ' La foce del Congo,' Atti R. Accad. Lincei, ser. 4, vol. ii. 

 pt. 1 (1886), pp. 510-513 ; see also Ernst Linbardt, ' Ueber unterseeiscbe Fluss- 

 rinneu,' Jahresber. Geogr. Gesellscb. Miincben [1890-91], 1892, pp. 26-27, 

 41-42. It is fair to note, bowever, tbat this case is not regarded as a proof of 

 subsidence by J. Y. Buchanan, ' On the Land Slopes separating Continents and 

 Ocean Basins, especially those on the West Coast of Africa,' Scottish Geogr. 

 Mag. vol. iii. (1887) pp. 222-223. 



