THE PALyiS OF BRITISH INDIA AND CEYLON. 369 



• ■" The distribution of the Desert Pahii appears to have been 

 deternuned by the boundaries of the great lake which, in the' not 

 very distant part, occupied the central depression of the Colorado 

 Desert. We may reasonably suppose the shores of this ancient 

 lake to have been enlivened, here and there, with groves of stately 

 ; palms. A few venerable trees still linger near the upper shore 

 .. line of this vanished sea, gaunt and ready to perish, and without 

 offspring to succeed them ; but the most have retired to the 

 caiions of the surrounding mountains. Here they find congenial 

 homes along the few and feeble streams, by some scanty spring, or 

 narrow oasis moistened by alkaline percolations. The necessity 

 of soil moisture is the governing factor in their distribution. 



" The most extensive groves occupy a tract of strongly alkaline 

 soil along the foothills some ten miles north of Indio, and extend- 

 ing some of the neighbouring washes. This belt may be considered 

 the centre of distribution. The finest grove occupies, for a mile 

 or more the narrow Palm Canon, on the opposite side of the desert 

 at the base of San Jacinto Mountain. Here hundreds of fine trees 

 fill the sandy bed of the stream or cling to the rocky bases of its 

 steep sides. The older trees are still vigorous, and there are 

 abundant younger ones of all sizes. 



"Most of the caiions at the- desert bases of San Jacinto 

 contain palms. A few grow in the caiion of the Whitewater, 

 which is the western limit of the species. Its southern outpost 

 is probably at Carrizo Creek ; a few trees at Corn Springs mark 

 its northern limit, and none are known east of Frink's Station." ^ 

 , DuKATiON OF LEAVES. — ;The functional life of a leaf is about 

 one year. How long the dead leaves would remain attached to 

 the trunk if undisturbed cannot be stated. Parish mentions a 

 row of trees in San Bernardino over 30 feet high from which the 

 leaves have never been removed, and the lowest are over 25 years 

 old and still firmly attached to the trunk. 



The thatch of dead leaves makes an admirable protection to the 

 trunk from the scorching heat and drying winds of the desert. 

 Unfortunately most trees have been deprived of this mantle. Its 



^ Parish S. B. A contribution toward a knowledge of the Genus Washingtonia, 

 in Bot. Gaz., Vol. 44 (1907), 426, 



