From Twenty-Five Years in a Waggon in South Africa: Sport and Travel in South Africa by Andrew A. Anderson, 1887:
… At Narukus, on the Nosop river, I came upon a family of Bushmen, ten in number, of a different type to those I had in my service, evidently a lower caste. They have no forehead; the wool on their heads comes close down to the eyes, and the head falling back like a baboon; projecting mouth, small nose, a sort of hair or wool all over the chest, arms, and legs; their eyes are small and restless, watching every movement that is going on; the tallest man did not exceed four feet four; their skin was of a reddish-brown. A few old skins, broken ostrich eggs, and bows and arrows, seemed all they possessed of worldly goods.
They would have decamped and hid in the bush, but I sent some of my Bushmen and brought them back. I asked my own boys, if they were their brothers, meaning of the same race; they repudiated the idea, and said they were monkeys not men, and told me there were very few ever seen, it was very seldom they ever came upon any; they eat carrion. They are evidently a distinct race from the Masara Bushmen who are largely distributed over the desert. One of the women had a baby not much bigger than a half-grown kitten; all of them were destitute of clothing.
It’s not uncommon for there to exist legends of little people who used to be here: e.g., Hawaii’s implausible Menehune (it’s really hard to get to Hawaii).
But this curious account in the middle of an otherwise level-headed memoir of tiny, hairy, foreheadless little people in southern Africa in the mid-19th Century is strange even by the standards of little people legends: the Bushmen who Anderson employs don’t offer a name for them, say they are very rare, and mostly seem annoyed by them for racist reasons.
And I haven’t heard of anybody mentioning them since.
The simplest explanation would be that they didn’t exist, that Anderson is either punching up his book with fiction or perhaps he encountered a family deformed for some medical reason such as inbreeding.