The American Deserts 



x 59 



flora and is centrally located with refer- 

 ence to the deserts of Texas, Chihua- 

 hua, New Mexico, California, and So- 

 nora. The town has a population of 

 10,000, who have presented the labora- 

 tory with a convenient site and have 

 aided it in many other ways. 



Tucson, for centuries before the land- 

 ing of Columbus, was one of the per- 

 manent settlements of the ancestors of 

 the Papago Indians of today. These 

 Indians were partly migratory, moving 

 southward in autumn to hunt in the 

 sierras during the winter and returning 

 in spring to replant their crops. 



They scoured the Sonoran plains for 

 chance water- holes, as well as more 

 permanent waters, carrying religiously 

 hoarded seeds ; they chased rainstorms 

 seen from commanding peaks for scores, 

 if not hundreds, of miles, and wherever 

 they found standing or running water, 

 or even damp soil, they planted their 

 seeds, guarded and cultivated the grow- 

 ing plants with infinite patience, and, 

 after carefully harvesting the crop, 

 planted some of the finest seeds as ob- 

 lations and preserved others against the 

 ensuing season, so that the crop plants 

 were both distributed and improved 

 from year to year. 



It was among the desert hills west of 

 Torres that the writers had an opportu- 

 nity to see a Papago Indian extract from 

 a bisnaga( Echinocactus emoryi) , or barrel 

 cactus, water with which to quench his 

 thirst. He cut the top from a plant 

 about five feet high, and with a blunt 

 stake of palo verde pounded to a pulp 

 the upper six or eight inches of white 

 flesh in the standing trunk. From this, 

 handful by handful, he squeezed the 

 water into the bowl he had made in the 

 top of the trunk, throwing the discarded 

 pulp on the ground. By this process 

 he secured two or three quarts of clear 

 water, slightly salty and slightly bitter 

 to the taste, but of far better quality 

 than some of the water a desert traveler 

 is occasionally compelled to use. The 



Papago, dipping this water up in his 

 hands, drank it with evident pleasure 

 and said that his people were accus- 

 tomed, not only to secure their drink- 

 ing water in this way in times of ex- 

 treme drouth, but that they used it also 

 to mix their meal preparatory to cook- 

 ing it into bread. 



WHAT IS A DESERT? 



The current conceptions of deserts are 

 neither adequate nor correct if the de- 

 scriptions in the best dictionaries and 

 cyclopedias are to be taken as an index. 

 A work of wide circulation and use de- 

 fines a desert as "A region that is wholly 

 or approximately without vegetation. 

 Such regions are rainless, usually sandy, 

 and commonly not habitable." 



The insufficiency of the above descrip- 

 tion rests upon faulty observations and 

 upon the failure to recognize the fact 

 that the habitability of a region is no 

 criterion of its arid character. The de- 

 velopment of modern methods of trans- 

 portation has made possible the mainte- 

 nance of dwellings and towns with a 

 considerable population at one or even 

 two hundred miles from the nearest 

 supply of water. Even such facilities 

 are not necessary to the sustenance of a 

 population in deserts of the most extreme 

 type, as illustrated by the Sahara, which 

 has a population of two and a half mil- 

 lion people. So far as the vegetation is 

 concerned, the actual number of indi- 

 viduals is much less than on a similar 

 area in a moist climate. This, in fact, 

 is one of the chief characteristics of a 

 desert, but it would not be safe to esti- 

 mate the total number of species much 

 below the average number. Lastly, be 

 it remembered that local topography has 

 but little influence on the desert char- 

 acter of a region. Sandy flats, plains, 

 valleys, and rocky hills reaching to such 

 altitudes as to become mountains are in- 

 cluded in some desert tracts. It follows 

 as a natural consequence of the sparse 

 vegetation as one factor that the surface 



