170 On the Campus 



change at any given instant has not been great ; the slow 

 upheaval of these mountains, their peaceful gentle re- 

 moval by the winds and rain; that is all; that has 

 changed and is changing the living world. Where the 

 terrestrial call is rude or sudden, response there is none. 

 The lava beds show no single characteristic species. 

 Their flora is simply that of their own rocky level. Nor 

 could here any sudden initiative on the part of the plant 

 avail. The adaptation is absolute now, and to vary save 

 as the environment varies would simply invite disaster. 

 As well the tadpole suddenly assume lungs or the lizard 

 put on feathers. 



Nor is this all. Our desert as it lies shining here be- 

 fore us is but a fraction of that wider, vaster desert that 

 covers all the south and west. Across the Organ and 

 San Andreas yonder is another desert exactly compar- 

 able to that we study; all Arizona, southern California, 

 Sonora, Chihuahua, much the same; here and there a 

 mountain summit tufted with forest, western in type, 

 high slopes thinly clad with stunted juniper, benches of 

 covillea, wide low plains covered with mesquite, with 

 yucca and cactus and all the less noble plants that stand 

 between; and our problem widens, becomes vast as the 

 continent, and any answer that we make must be far- 

 reaching as the flora of a world. 



Our desert lies shining here before us ; but not one of 

 these plants except the cactus is in broader sense unique ; 

 each has its kin rising in happier fields to fairer fortune. 

 The yuccas are lilies, but lilies bloom in Bermuda and 

 in Teneriffe, and in every most fertile garden of the 

 world. The mesquite is a prosopis, but the genus Proso- 



