But though Wadi Ibib itself is barren, it has some great tributaries which contains abundance of trees and scrub in their upper reaches, as well as several wells. The principal of these tributaries are the Wadis Soaorib and Um Bishtit, which with their feeders drain the mountains of Soaorib, Qidmib, Orgem, and Um Bishtit, while other smaller tributaries drain the lower hills north-east of Um Bishtit and Gebel Hamra Dom. =Wadi Soaorib= originates in the midst of high mountains a little south of latitude 22° 10′, between the southern portion of Gebel Soaorib and the range which extends southwards from Hadal Aweib Meisah. At its head is a difficult pass westward into the head of Miti Kwan, a tributary of Alaqi. Curving at first eastward, it soon takes on a north-westerly direction, and in latitude 22° 11′ 30″ reaches a small open space called =Mitba=; here it is met by several tributary wadis of which the principal is the =Wadi Haiyo=, draining the eastern slopes of Gebel Soaorib. From Mitba the direction of Wadi Soaorib becomes more northerly, and about nine kilometres below Mitba it turns to the west, emerging from the mountains into the more open country which forms the south end of the great plain already referred to. Here it is joined by the =Wadi Hankuk=, draining north-eastward from Gebel Adar Qaqa, and a few kilometres further on by the =Wadi Dishlo=, which drains the western flanks of Hadal Aweib Meisah and enters Soaorib from the east. About three kilometres below the point of influx of Wadi Dishlo, Wadi Soaorib is joined from the south-west by another tributary which drains the west side of Gebel Um Seleim. From this point onwards, Wadi Soaorib courses a little east of north in a not very well defined course for about twenty-two kilometres over a gently falling sandy plain, joining Ibib to the north-west of the sand-swathed hills called Baqari Daba. In this part of its course, Wadi Soaorib receives small feeders from among the hills west of it on the plain, the principal of them draining north-eastward between the hills called Kulet Meiqrum and Kulet Tinasal. It also receives more important tributaries from the mountains to the east of it, the principal of these being the Wadis Eimya and Qidmib. =Wadi Eimya= drains the western face of Gebel Qidmib, while =Wadi Qidmib= drains the northern parts of the same mountain. Wadi Qidmib has two main heads; the western one lies between two high mountain ridges, and contains a well called =Bir Qidmib=, while the eastern one leads to a steep pass by which Wadi Meisah can be reached. Before reaching Wadi Soaorib, Wadi Qidmib is joined by other feeders draining the western flanks of Gebel Orgem and Baqari Daba.