xii LIST OF ILLUSTRATIONS 



FIG. 



10. Artificial Depressions in Sand Dunes at El Wad, S. 



Algeria, planted with Date Palms which are drawing 

 on Subsoil Water. The sharp margin of the oasis and 

 the utterly barren nature of the dunes are apparent. 

 {Photo : V. H. W. Dowson, July, 1922) facing p, 42 



11. Ridge of Cretaceous Limestone hollowed and carved by 



Wind-driven Sand, at Umm Shersher, S. of Kliarga 

 Oasis, Libya. (Photo : F. W. Green, Greol. Survey 

 of Egypt) facing p, 42 



12. Date Palm growing in a Pit at El Wad, S. Algeria. The 



contrast between the flourishing palm which has 

 tapped the subsoil water and the utter absence of any 

 undergrowth is striking. The palm-leaves inserted in 

 the sand in the foreground are intended to check 

 drifting sand. (Photo : V. H. W. Dowson, July, 

 1922) facing p. 44 



13. Bare Expanse of Salt Mud at the North End of the Dead 



Sea, Palestine, with two or three tufts of salt-loving 

 bushes : within the historical era this area was 

 beneath the waters of the Dead Sea. (P. A. Bux- 

 ton, photo) facing p. 44 



14. Salt Patch in Lower Mesopotamia. The white area is 



covered with crystals of salt ; the darker margin lies 

 a few inches higher, and is therefore slightly less salt : 

 the few small bushes are Suseda. (V. H. W. Dow- 

 son, photo) ..... facing p. 46 



15. Salt-loving Vegetation (Atriplex halimus, etc.) on 



the Plain of Jericho, Palestine. (P. A. Buxton, 

 photo) ...... facing p. 46 



16 & 17. Hills near the Mouth of R. Jordan, near Jericho, 

 Palestine. These hills contain such a high propor- 

 tion of salts that they are almost entirely bare of 

 vegetation. (P. A. Buxton, photo) . facing p. 48 



18. Wadi Nar, S.E. Palestine. This is typical of a certain 

 type of rock desert, in which the strata of bare rock 

 alternate with softer material ; it is full of crevices 

 and on it grow a large number of spring flowers, and 

 it contains caves (pages 104-105). Typical birds are 

 Rock Doves, Black and White Wheatears (Saxicola 

 lugens)^ Rock Partridge (Alectoris), Ravens (Gorvus 

 ruficeUis), and Tristram's Grackle (Amydrus tris- 



