CH. V. AJiN OUMAST. 107 



per mile from south to north, as it slopes from the foot of 

 the Great Atlas towards the river Tensift, and a further 

 slighter dip of about ten feet per mile from east to west, 

 between the city of Marocco and Sheshaoua. The defici- 

 -ency of water at once explains the great change ia the 

 vegetation, which was speedily perceptible in detail, but 

 obvious to the eye from the first view of the country newly 

 opened before us. Corresponding to this is a considerable 

 change of climate, arising from the rapid heating of the 

 surface by day, and the no less rapid cooling by radiation 

 at night. We are already far from the equable climate of 

 Mogador ; and although the air in the shade is only plea- 

 santly warm, we are happy to have the protection of pith 

 helmets covered by turbans between our heads and the 

 direct rays of the sun. 



The verge of the great plain over which we rode this 

 afternoon is far less barren than the portion which yet lay 

 before us ; and we found several species characteristic of 

 similar situations in Spain and Africa, along with some 

 others, hitherto undescribed, that appear to be character- 

 istic of this part of Marocco. Thus Artemisia Herha alba 

 became conspicuous, in some places almost covering the 

 surface. Of the more noticeable herbaceous plants here 

 seen were Matihiola parvijlora, Gypsophila compressa, 

 Ebenus pinnata (rather common throughout the low 

 country), Onohrychis crista galli, an Elceoselinum, near to 

 E. meoides, and numerous Compositce, of which Cladanthus 

 arabicus is one of the most conspicuous. We did not notice 

 the fragrant odour which some travellers have found in the 

 flowers of this species. To the same natural Order belong 

 several undescribed plants, which became more abundant as 

 we advanced into the interior of the country, belonging to 

 the genera Anacyclus, Matricaria, Anthemis, and Cen- 

 taurea. 



About half-past four we reached our appointed camping 

 place, at Ain Oumast, one of the few wells of drinkable 

 water found in the region we had now entered. In the coast 



