

HABITAT OF THE COAHUILLAS 31 



"salses" that have thrown up mud cones three to fifteen feet high about 

 their orifices. Masses of mud with jets of hot water are thrown up, 

 sometimes to a height of many feet, and vapors of water, sulphur, and 

 sal ammoniac are thrown off with eruptive explosions audible for 

 many miles. One of these bubbling mud springs occupies a crater- 

 like depression twenty-five feet deep near the station called Volcano 

 on the Southern Pacific railroad. 1 



The atmospheric conditions are fully in keeping with the other 

 features of the desert. A temperature in summer during the day- 

 time of 1 15- 1 20 is not uncommon in the coolest and shadiest spot 

 attainable. Owing to the exceeding dryness of the air, however, moisture 

 from the body evaporates very rapidly, and even this extreme heat is 

 not very hard to endure. A large supply of water is, however, for the 

 white man an essential. Through the whole course of the desert, 

 from Yuma to San Gorgonio there rages much of the time a furious 

 storm of wind and sand. Its effects are most curious. The moun- 

 tains on the northern side of the pass are piled almost to their summits 

 with drifted sand. Enormous dunes collect at this side of the 

 valley and vast stretches of the desert are left as smooth and clean of 

 vegetation as a plowed and harrowed field. The wagons of parties 

 crossing the desert along this one hundred and fifty mile sand-swept 

 line are buried to their boxes every night by the drifted sand piles. 

 The effects of this silica-laden wind are as terrific as a sand-blast. 

 Telegraph poles are rapidly worn away and have to be frequently 

 renewed. The windows of the section houses or pieces of broken 

 bottles left on the sand are soon converted into ground glass. 



Rain seldom falls on this desert in a natural manner. When it 

 comes it is in terrific water-spouts or cloud-bursts that flood the 

 country briefly like a lake and cut great gullies, twenty-five feet deep, 

 in the sand. For miles the railroad track is little but a succession of 

 culverts bridging these steep barrancas. 



14. Some portions of the desert, as we have noticed, support 

 quantities of the mesquite as well as the agave ; others are absolutely 

 destitute of any vegetation whatever. Among characteristic plants 

 are the Larrea Mexicana or "creosote bush," so called because of its 

 peculiar odor. Its leaves are small and sticky, and it bears a yellow 

 flower. The "palo verde" (Parkensonia Torreyana) is so named by 

 the Mexicans because of the pale green color of its branches. Its 



1 For a more extended account of these mud volcanoes, as well as of the Colorado overflow, see the 

 present writer's article, " The Colorado Desert," in the National Geographic Magazine for September, 

 1900. 



