PAPAGUERIA 349 



leys the deep-rooted mesquite dots the surface in similitude of 

 scattered and ill-kept orchards, or gathers with a dozen other 

 trees in scraggy forests along permanent waterways, while mon- 

 strous bizarre cacti haunt the foothills and the lower slopes, and 

 scattered grass-blades faintly tinge the acres intervening between 

 cacti and mesquites. The plant forms abound in pulpy struc- 

 tures and impervious rinds for conserving moisture, even more 

 than in thorns and other protective devices; for in this hard 

 region the struggle for existence is not so much between organism 

 and organism as between organism and environment, and the 

 organisms persist less by the multiplication of progeny than by 

 the prolongation of individual life. Animal life, in insect, rep- 

 tile, bird, and mammal, occurs in much the same proportion to 

 vegetal life as in humid regions, but is more largely nocturnal 

 and crepuscular. Ants of many kinds (including the ingenious 

 and successful farmer ant), wasps, flies, and other insects follow 

 the sparse flora. Gaudy and swift efts, as well as somber and 

 sluggish lizards, accompany the insects, while ground-squirrels 

 and field-mice contribute a quota of vitality. In the more humid 

 valleys, and on the mountain sides moistened by drainage from 

 above, rabbits, quail, deer, and other herbivorous and graminiv- 

 orous things collect in limited numbers, while serpents find sub- 

 sistence in the more fertile spots ; and over the hills, valleys, and 

 plains on which lower life prevails the coyote on the land, and 

 hawks, owls, and eagles in the air, are not wanting (for it is only 

 in the western part of Papagueria, where the rainfall is trifling, 

 that life is unable to hold its own). Yet, as among plants, the 

 struggle of animal life against inorganic nature and alien organ- 

 isms is severe, and an exceptional number of the animate things 

 are armed with mandibles, stings, fangs, talons, poison glands, 

 and other protective devices. The distribution of life conforms 

 to the distribution of water ; it is most abundant over the rugged 

 summits and rocky slopes of the high Sierra, as well as along the 

 gulches and gorges — barrancas of the local vernacular — of the 

 foot slopes and the broad sand washes or arroyas of the narrower 

 valleys; it is less abundant on the foothills and over the lower 

 ranges, where the storms are feebler and rarer ; it is still more 

 meager over the broad intermontane valleys constituting the 

 greater part of Papagueria ; but it is only in the western portion 

 of the district, where clouds rarely gather and whither streams 

 never flow, that the shifting sands and black-burned scoria? of 

 dead volcanoes (the "mal-pais" of the Mexicans) are utterly 

 barren. 



