The kalahari is not easy place to know. It is still less easy to understand. Rapid journeys through that wilderness seem to engender views regarding its aspects and hypotheses concerning its history that closer and more protracted studies fail to support. Certainly, nine years of close acquaintance with the Kalahari and much work in it, have so fashioned my conclusions that I find myself unable to agree with all that Professor Debenham has so interestingly chronicled in the March 1952 number of this Journal. Indeed, several of his disclosures discord strongly with my personal knowledge of the thirstland, and with that of other competent and long resident observers in the country. Reluctant as I am to do so, I feel bound to call attention to some of these statements which, if allowed to stand, will certainly lead to much unfortunate misapprehension. Professor Debenham writes of the Kalahari that almost everywhere there is a surface covering of fine yellowish calcareous sand from 5 to 500 feet in thickness . . . distributed just as it is in a true desert in ridges and dunes. One can hardly recognize the Kalahari in this description. Du Toit writes of it as follows: an uninterrupted mantle of transported red to grey sands resting on a peneplained surface. * Although surface discolouration in many places disguises the fact, the Kalahari sand is characteristically red, but because this statement may seem to involve a matter of discrimination, it leads to the question which I shall shelve for the moment, of What do you mean by Kalahari sand? Let us for the moment discuss the sands of the Kalahari. These are of several colours but red is quite the most predominant. Yellow and yellowish sands, to nearly white and white certainly occur but these are reblown or bleached red sand.2 There is, too, important deposit which covers very wide areas of flat country. It is dark brown and powdery when dry, but it generally appears grey at surface, in consequence of the sluicing action of rain which removes the more easily transported fractions and leaves most of the tiny polished sand grains with which the deposit is packed. When wet, the material is very nearly black, and slippery. A number of dunes, particularly in the south-west of the Protectorate, are built of reblown and therefore yellowish sand. They yield interesting microlithic culture, with ostrich tgg shell beads. Much of this sand is on the move again, and is producing dune patterns which defy description. In the neighbourhood of the Nosob-Molopo confluence one sees wire fences with wide gaps below them in places, so that one can walk under the wire. In