A curious result of these relations is that in the wooded districts some of the natives have reverted to arboreal habits, taking refuge during the raids in the branches of huge bombax-trees converted into temporary strongholds. Round the vertical stem of these forest giants is erected a breast-high look-out, while the higher horizontal branches, less exposed to the fire of the enemy, support strongly-built huts and store-houses, where the families of the fugitives take refuge with their effects, including, as Nachtigal assures us[192], their domestic animals, such as goats, dogs, and poultry. During the siege of the aerial fortress, which is often successfully defended, long light ladders of withies are let down at night, when no attack need be feared, and the supply of water and provisions is thus renewed from _caches_ or hiding-places round about. In 1872 Nachtigal accompanied a predatory excursion to the pagan districts south of Baghirmi, when an attack was made on one of these tree-fortresses. Such citadels can be stormed only at a heavy loss, and as the Gaberi (Baghirmi) warriors had no tools capable of felling the great bombax-tree, they were fain to rest satisfied with picking off a poor wretch now and then, and barbarously mutilating the bodies as they fell from the overhanging branches. Some of these aborigines disfigure their faces by the disk-like lip-ornament, which is also fashionable in Nyassaland, and even amongst the South American Botocudos. The type often differs greatly, and while some of the widespread Mosgu tribes are of a dirty black hue, with disagreeable expression, wide open nostrils, thick lips, high cheek-bones, coarse bushy hair, and disproportionate knock-kneed legs, other members of the same family astonished Barth "by the beauty and symmetry of their forms, and by the regularity of their features, which in some had nothing of what is called the Negro type. But I was still more astonished at their complexion, which was very different in different individuals, being in some of a glossy black, and in others of a light copper, or rather rhubarb colour, the intermediate shades being almost entirely wanting. I observed in one house a really beautiful female who, with her son, about eight or nine years of age, formed a most charming group, well worthy of the hand of an accomplished artist. The boy's form did not yield in any respect to the beautiful symmetry of the most celebrated Grecian statues. His hair, indeed, was very short and curled, but not woolly. He, as well as his mother and the whole family, were of a pale or yellowish-red complexion, like rhubarb[193]."