Apart from the influences of elevation, heat, humidity, and degradation, I have imagined that the lighter and darker colors observed in the native population run in five longitudinal bands along the southern portion of the continent.  Those on the seaboard of both the east and west are very dark; then two bands of lighter color lie about three hundred miles from each coast, of which the westerly one, bending round, embraces the Kalahari Desert and Bechuana countries; and then the central basin is very dark again.  This opinion is not given with any degree of positiveness.  It is stated just as it struck my mind in passing across the country, and if incorrect, it is singular that the dialects spoken by the different tribes have arranged themselves in a fashion which seems to indicate migration along the lines of color.  The dialects spoken in the extreme south, whether Hottentot or Caffre, bear a close affinity to those of the tribes living immediately on their northern borders; one glides into the other, and their affinities are so easily detected that they are at once recognized to be cognate.  If the dialects of extreme points are compared, as that of the Caffres and the tribes near the equator, it is more difficult to recognize the fact, which is really the case, that all the dialects belong to but two families of languages.  Examination of the roots of the words of the dialects, arranged in geographical order, shows that they merge into each other, and there is not nearly so much difference between the extremes of east and west as between those of north and south, the dialect spoken at Tete resembling closely that in Angola.

Having, on the afore-mentioned date, reached the village of Njambi, one of the chiefs of the Chiboque, we intended to pass a quiet Sunday; and our provisions being quite spent, I ordered a tired riding-ox to be slaughtered.  As we wished to be on good terms with all, we sent the hump and ribs to Njambi, with the explanation that this was the customary tribute to chiefs in the part from which we had come, and that we always honored men in his position.  He returned thanks, and promised to send food.  Next morning he sent an impudent message, with a very small present of meal; scorning the meat he had accepted, he demanded either a man, an ox, a gun, powder, cloth, or a shell; and in the event of refusal to comply with his demand, he intimated his intention to prevent our further progress.  We replied, we should have thought ourselves fools if we had scorned his small present, and demanded other food instead; and even supposing we had possessed the articles named, no black man ought to impose a tribute on a party that did not trade in slaves.  The servants who brought the message said that, when sent to the Mambari, they had always got a quantity of cloth from them for their master, and now expected the same, or something else as an equivalent, from me.