We started late on the 6th, for the Tuaricks had allowed their camels to stray, and we waited some time for them: however, we were obliged, after all, to start without them, and having made five hours and a half halted. Our course had lain over the plateau, which about half way became broken up into valleys. One of these, called Anan Haghaneen, led us into the pleasant and picturesque wady of Mana Samatanee, where only in this part of the route can be found herbage for camels. There are also a few tholukh-trees. What a desolate region is all this, despite the little spots of vegetation! There are no signs of animal life, except traces of the wadan. For two days, they tell us, we are to have little or no water. Now and then we pass desert mosques,--square, or circular, or cross-shaped walls of stone, some with two entrances, built for the devotion of chance passengers. The mountains on the east are called El Magheelaghen. To-day we carried my trunk with the money. Yusuf had previously given it in charge to a camel-driver, and the Tuaricks were always uneasy, asking to see if all were right. Europeans would probably have done the same under similar circumstances. On the 7th we made a good day of about eleven hours, continuing during the first three in shallow wadys, down one of which we had a distant view of the plain of Serdalous, on the north-west. Then came the breaking up of the great plateau of Fezzan, and we entered a pass which leads down into the subjacent Sahara, and runs west with an inclination to the south. This is, perhaps, one of the most extraordinary natural features I have ever beheld. It seems to have been purposely cut out of the solid rock for the use of man, and reminds one at first of a railway excavation. As we advance it assumes the form of a cave, slightly open at top,--narrow, winding, and furnished with seats on either hand. A dim light comes from above. Only one part was difficult for the boat. Now and then the pass became quite a tunnel, but the concave roof is high enough for any camel to pass. On the sides, here and there, were Tuarick inscriptions; but there was nothing remarkable revealed by this admirable geological section. It was mostly sandstone for the upper strata, with narrow streaks of marl and chalk. Some slate was observed, and frequently our way lay over beds of red clay. An agreeable surprise awaited us occasionally, in the shape of little openings containing groups of the tholukh; but the general aspect of the pass was horrible and desolate, and we eagerly pushed on towards the end. There was nothing, apparently, to support life; but we found and caught a young fox: how the little wretch procured food was a mystery which our guides could not explain. However, life no doubt had its joys for him, and we let him loose in the plain below. I also picked up a dead bird, of a species common in the desert, with white head or cap, and white tail, except the upper feathers; all the rest, legs and bill, black.