210 VEGETATION OF THE MIDDLE ZONE. cii. ix. 



variety of the white poplar — and Salix purpurea, with 

 walnut, olive, and carob, the latter three being extensively 

 cultivated. The small-leaved ash, Fraxinus oxyphylla, 

 was also rather common, but does not grow to so large a 

 size as in North Marocco. On drier ground, on the stony 

 slopes, Ccdlitris occurs here and there ; and two jumpers 

 — /. oxycedrus and J. phoenicea — are rather frequent, and 

 when allowed to reach maturity attain to the stature of 

 small trees. The evergreen oak is the predominant tree 

 on the flanks of the mountains, and exhibits several 

 varieties, but rarely attains its natural size. Shrubs and 

 low bushes, as usual in the Mediterranean region, are 

 very numerous and varied, most of them, such as the 

 alaternus, phillyrea, lentisk, oleander, and colutea, being 

 widely diffused species of Southern Europe ; and a beau- 

 tiful honeysuckle {Lonicera etrusca), with large, sweet- 

 scented flowers, was a conspicuous ornament. Along with 

 these, several common forms of Central and North-western 

 Europe, such as the common bramble, the ivy, the dog- 

 rose and elder, here find their southern limit. It was not 

 possible, however, for a botanist to look about him at any 

 spot in the valley without being struck by abundant 

 evidence that he had entered a region very distinct from 

 any part of Southern Europe or Algeria. This impression 

 was strengthened throughout our ride of the previous day, 

 ■BS we ascended from OTir camp to the foot of the ancient 

 moraine, and everywhere saw conspicuous plants peculiar 

 to the middle and lower zones of the Great Atlas. Our 

 first impression was that the proportion of such endemic 

 species was larger in this part of the valley than in the 

 higher zone ; but this was due to the fact, that so many 

 more of those inhabiting the lower zone strike the eye by 

 their greater size and by the brilliancy of their flowers. 

 "When we came to examine our collections with the requi- 

 site care, we found that about one-seventh of all the 

 species found in the middle region of this valley is made 

 up of peculiar endemic species, while the proportion 



