plains.  The inhabitants, Bushmen and Bakalahari, prey on the game and on the countless rodentia and small species of the feline race which subsist on these.  In general, the soil is light-colored soft sand, nearly pure silica.  The beds of the ancient rivers contain much alluvial soil; and as that is baked hard by the burning sun, rain-water stands in pools in some of them for several months in the year.

The quantity of grass which grows on this remarkable region is astonishing, even to those who are familiar with India.  It usually rises in tufts with bare spaces between, or the intervals are occupied by creeping plants, which, having their roots buried far beneath the soil, feel little the effects of the scorching sun.  The number of these which have tuberous roots is very great; and their structure is intended to supply nutriment and moisture, when, during the long droughts, they can be obtained nowhere else.  Here we have an example of a plant, not generally tuber-bearing, becoming so under circumstances where that appendage is necessary to act as a reservoir for preserving its life; and the same thing occurs in Angola to a species of grape-bearing vine, which is so furnished for the same purpose.  The plant to which I at present refer is one of the cucurbitaceae, which bears a small, scarlet-colored, eatable cucumber.  Another plant, named Leroshua, is a blessing to the inhabitants of the Desert.  We see a small plant with linear leaves, and a stalk not thicker than a crow’s quill; on digging down a foot or eighteen inches beneath, we come to a tuber, often as large as the head of a young child; when the rind is removed, we find it to be a mass of cellular tissue, filled with fluid much like that in a young turnip.  Owing to the depth beneath the soil at which it is found, it is generally deliciously cool and refreshing.  Another kind, named Mokuri, is seen in other parts of the country, where long-continued heat parches the soil.  This plant is an herbaceous creeper, and deposits under ground a number of tubers, some as large as a man’s head, at spots in a circle a yard or more, horizontally, from the stem.  The natives strike the ground on the circumference of the circle with stones, till, by hearing a difference of sound, they know the water-bearing tuber to be beneath.  They then dig down a foot or so, and find it.

But the most surprising plant of the Desert is the “Kengwe or Keme” (’Cucumis caffer’), the watermelon.  In years when more than the usual quantity of rain falls, vast tracts of the country are literally covered with these melons; this was the case annually when the fall of rain was greater than it is now, and the Bakwains sent trading parties every year to the lake.  It happens commonly once every ten or eleven years, and for the last three times its occurrence has coincided with an extraordinarily wet season.  Then animals of every sort and name, including man, rejoice in the rich supply.  The elephant, true lord of the forest, revels in this