Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. But it is in the most rudimentary adjustments to climate and geographic peculiarities that the genius of the native races is shown. Dowd tells how the Bushmen, living in the waterless Kalahari desert and having often to go without water for sev eral days, made even this environment yield them liquid. When they came to the dried bed of a river or pond, in pursuit of game, they would take a long reed and make a primitive filter by tying long grass around one end of this tube. They would then push the filter end as deep as possible into the muddy soil, allowing the water to slowly penetrate the filter. The water would then be drawn up by suction and discharged into an egg shell.