336 THE ZOOLOGIST. 



Neumann at Lake Rudolph : " Alongside a rocky gully, right 

 on the lake side, a patch of the black lava debris was covered 

 thickly with bleached bones. From a distance it looked like 

 snow, and I wondered what in the world it could be ; but on 

 getting close I found it to consist of the whitened bones of 

 ' Camels.' Hundreds must have perished here, all huddled in 

 one little corner." * A gradual desiccation is generally believed 

 to have prevailed in South Africa for a long time past, and the 

 process is not confined to that continent. According to Semon, 

 the climate and meteorological conditions of Australia are such 

 at present that a single drought of several years' duration can 

 and often does exterminate all the aquatic inmates of a river. 

 Few rivers have a lake-reservoir which they could feed upon in 

 times of drought. The lack of water-treasuring mosses is like- 

 wise a prominent feature of the Australian bush. A drought 

 setting in — and the short history of Australia tells us of periods 

 when not a single raindrop has fallen for three or four years in 

 a district known as commonly subject to rains — a whole river 

 area is liable absolutely to dry up, and its animals will be ex- 

 terminated, with exception of such as withstand desiccation in 

 either their fully formed or embryonic state.! Arabia, especially 

 the southern part, is stated to be still drying up. Water is dis- 

 appearing from places where it used to exist, and the inhabitants 

 are migrating towards Persia. The word famine is often an 

 equivalent to that of drought, but the results recorded are 

 usually confined to the destruction of human life, though we can 

 generally realize how many species of other animals and plants 

 have suffered and succumbed to these visitations. It may be 

 sufficient to refer to the great drought in Egypt in the year 1060, 

 when the Nile failed to flow for seven successive years, and one 

 of the greatest famines on record occurred ; in the years 1730-33 

 great drought and famine existed at the Cape de Verd Islands ; 

 whilst a similar event in India in 1876-78 is still in our own 

 recollection. 



It must be also remembered that, without actual extinction, a 

 drought will often effect great morphological changes in plants, and 

 that such may initiate constitutional weakness. Sign. Bolos wrote 



* ' Elephant- Hunting in East Equatorial Africa,' p. 261. 

 f ' In the Australian Bush,' p. 89. 



