CH. T. THE CAMEL'S BACK. Ill 



the increasing heat of the day, and ahead of us rose some 

 flat-topped hills of singular aspect which have attracted 

 the attention of all travellers in this region. Some of 

 these hills extend for a considerable distance, while others 

 form small isolated masses ; but they agree in two respects 

 — all are flat-topped, and all show a steep escarpment 

 especially on their westward faces. We afterwards saw 

 reason to believe that they all rise about 450 feet above 

 the portion of the plain near at hand, and reach nearly 

 the same height as the plain surrounding the city of 

 Marocco. The general appearance suggested the proba- 

 bility of a former wide extension westward of the latter 

 plain, and subsequent erosion by marine or fluviatile ac- 

 tion. As we approached the most conspicuous of these 

 isolated hills, we were struck with the singular appearance 

 of the stunted bushes of Zizyphus Lotus, which form the 

 only arborescent vegetation of this region. From a little 

 distance they looked as if covered by some white-flowered 

 climbing plant, or else laden with white fruit. This ap- 

 pearance was due to the extraordinary number of two 

 species of snails (Helix lactea and H. explanata) that 

 completely covered the branches. We frequently noticed 

 the same appearance afterwards, but nowhere so markedly 

 as here. 



Towards the foot of the first and most conspicuous of 

 the hills above mentioned, which bears the inappropriate 

 name Hank el Gemmel (Camel's back), the plain rises 

 gently rather more than one hundred feet in all ; above 

 this the slope of the hill becomes steep, and finally exhibits 

 an almost vertical face at the top. At the foot of the 

 steeper slope, about four hours' ride from Ain Oumast, 

 our track passed by an ancient well, now almost dry, and 

 often completely so ; and here, under the imperfect shade 

 of a lotus tree, we made a short halt. The direct rays of 

 the sun being very powerful, we were somewhat surprised 

 to find the temperature of the air to be only 77° Fahr. 

 Leaving our escort, we ascended the low but steep hill 



