128 CALIFORNIA DESERT TRAILS 



dark brown that reaches ten or twelve feet above 

 the level of the soil. Above this line the rock is 

 lighter, the ordinary granite weathered to red and 

 ochre. The so-called coral is what geologists call 

 travertine, really calcium carbonate, which in a 

 sort of sponge-like formation encrusts the rock that 

 was once submerged. Little shells are embedded in 

 the substance, or remain as they lodged in the inter- 

 stices when washed there by some wave of the van- 

 ished sea. 



The hill is cliff-like in steepness and almost bare 

 of vegetation. A biznaga or two lean out as if curious 

 to see the rare visitor, and a few thin creosotes wave 

 drearily in the wind. At the rear of the reef the 

 ground rises to a bench of gravelly soil in which one 

 notes at once a different set of plants — the smoke- 

 tree, palo verde, several sorts of cactus, bright- 

 green creosote, and the odd sandpaper plant. There 

 is always this well-marked difference between the 

 vegetable life of tracts above and below sea-level, 

 the difference being based, of course, upon the dis- 

 tinct characters of the soils. Above the old sea-line 

 is sand, gravel, and rock, with a varied range of 

 desert growths; below is a fine silt whitened with 

 shells and with little vegetation beyond dull clumps 

 of atriplex and suseda. This lower belt is much the 

 drearier region: yet it is this selfsame silt which, 

 where not rendered sterile by alkalinity, shows 

 such amazing fertility under cultivation. It is Lower 

 Egypt over again, with the Colorado taking the 

 place of the Nile. 



A little distance to the west I noticed a small 



