TREES AND TREE-LIKE GROWTHS 39 



so opposite to our thought of out-reaching branch, 

 shady gallery, and spreading contour). But I have 

 spoken of the palm at length in another chapter. 

 And, after all, it is rather an incident of the desert 

 than a characteristic, appearing only sporadically 

 and as a rule about the margins of the territory, 

 limited always to the rare spots that yield the need- 

 ful conditions of moisture. 



The principal desert tree is the mesquit. Of this 

 there are two species, differing in size, mode of 

 growth, and some other details, the most noticeable 

 of which is the seeding. The larger, Prosopis glan- 

 dulosa, bears a typical bean, the other, Prosopis 

 pubescens, a unique seed-vessel exactly like a rather 

 large screw. From this feature the latter tree takes 

 the name of "screwbean," or tornillo, the Spanish 

 word for screw. 



The larger mesquit is the one great benefaction 

 of Nature to her desert-dwellers. Were it only in the 

 matter of shade, what songs should be raised to it 

 by man, bird, and beast; and indeed are raised by 

 sparrow, wren, linnet, and, to the best of his ability, 

 by that arch black sprite, phainopepla, who thinks 

 the topmost spray of a mesquit the cap of the uni- 

 verse! Reptile and insect revel in it too, for, as I 

 write these pages under the shade of a mesquit 

 (driven from my tent by a mid-morning March 

 temperature of 108°), I am buzzed and bitten by 

 gnats and flies of all degrees, cobwebbed by spiders, 

 explored by serious beetles, and adopted by cater- 

 pillars as a happy idea: while nimble lizards scam- 

 per about sniping my tormentors. Every mesquit is 



