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 fruit, and so do the different species of rhinoceros, although naturally so diverse in their choice of pasture. The various kinds of antelopes feed on them with equal avidity, and lions, hyaenas, jackals, and mice, all seem to know and appreciate the common blessing. These melons are not, however, all of them eatable; some are sweet, and others so bitter that the whole are named by the Boers the "bitter watermelon". The natives select them by striking one melon after another with a hatchet, and applying the tongue to the gashes. They thus readily distinguish between the bitter and sweet. The bitter are deleterious, but the sweet are quite wholesome. This peculiarity of one species of plant bearing both sweet and bitter fruits occurs also in a red, eatable cucumber, often met with in the country. It is about four inches long, and about an inch and a half in diameter. It is of a bright scarlet color when ripe. Many are bitter, others quite sweet. Even melons in a garden may be made bitter by a few bitter kengwe in the vicinity. The bees convey the pollen from one to the other.