NATURALIST IN CALIFORNIA. 471 



not over a mile wide. The whole upland has a most barren 

 and desolate aspect, the only vegetation being low shrubs of 

 the fetid Larrea Mexicana, with cacti and other tliorny 

 plants beneath. The bottom land, however, supi)orts a 

 vio-orous growth of cottonwood, willows, and niesquite, 

 a name applied there to two quite ditierent trees, the Alga- 

 robia glandulosa and 8ti'omhocarpa jmbescens. Dense shrub- 

 bery and coarse grasses cover most of the ground, even 

 under the darkest shade, though spots are sometimes too 

 alkaline for any vegetation except a few sea-shore plants, 

 and in places the winds keep up a rolling waste of sand 

 hills. The river itself is so low in winter that the Indians 

 can wade across with their heads above water, and is so 

 muddy as to fully deserve its name. 



After my desert experience, I gazed with delight on the 

 broad flashing stream, with its forest-clad banks, even though 

 the trees were then bare, and the whole country nearly of 

 the same brown tint as the river, for I knew that the very 

 barrenness of the surrounding regions must drive most of 

 the animal life to the river banks, one class in search of 

 vegetable food the other to prey upon the former, while 

 such as loved water must necessarily seek it here. And, 

 with the exceptions mentioned as desert animals in my for- 

 mer article, nearly all of the higher animals are confined to 

 this narrow belt of timber, stretching along the course of 

 the Colorado from its Great Canon, thirty miles higher up, 

 down to its mouth. Those living permanently on the up- 

 lands must depend on a very scanty supply of dew for water 

 during most of the year. 



I must remark here that in climate this region belongs to 

 Mexico, the winter being the drj/ season, and the summer 

 subject to violent thunder storms from the south, but not 

 wet, the whole annual rain not exceeding three or four 

 inches, of which perhaps one falls in winter. The tempera- 

 ture rarely falls below the freezing point in latitude od°, 

 althouirh the surroundins: mountains were white with snow 



