Chap. IX] 



DESERTS 



615 



Fig. 347. Capparis spinosa, var. 

 aegyptica. Transverse section of 

 leaf. Magnified 40. After Volkens. 



Fig. 346. Aiistida pungens. Transverse section of leaf. 

 Magnified. After Tschirch. 



Fig. 349. Mesembryanthemum crystal- 

 linum. Transverse section of stem. 

 Magnified. After Volkens. 



Fig. 34S. Neurada procumbens. Transverse section 

 of leaf. Magnified 140. After Volkens. 



in combination in the majority of perennial plants of the Sahara (Figs. 

 346-349). In the Sahara, however, such striking specimens as the South 

 African desert affords, especially in its cactus-like species of Euphorbia 



