24 BOTANY. 



feelings on being somewhat unexpectedly brought face to face with this 

 peculiar vegetation would be futile, as no point of comparison appears to 

 offer. The giant Cereus occupies the hill-sides which have a southern and 

 southeastern exposure, towering up to a height of from 30 to 50 feet. 

 Fouquieria, with its leafless, wandlike trunk, and its tip of scarlet flowers, 

 Agave Palmeri and Parryi, and various species of Dasyliriwm, dry, rigid 

 skeletons of plants without the living green ; Canotia, a tree 20 feet high, a 

 foot in diameter, with green branches provided with stomata, but no leaves, 

 all go to complete this desolate floral landscape While the Mimosa, Acacia, 

 and Caliandrce, rising to the dignity of trees or dwarfed to mere underbrush, 

 inhabit the less dry hillsides and ravines, but still by their small leaves 

 and hardened tissues show that they too have the impress of the dry, hot 

 air about them. What the vegetation and climate of this valley may once 

 have been we have now no means of certainly knowing. It is, however, in 

 the highest degree probable that the process of desiccation, which has long 

 been taking place in portions of New Mexico, is going on here. Along the 

 higher bluffs back from the river, and far away from any chance of irriga- 

 tion, one still sees the ruins of ancient pueblos, and in places traces of 

 agricultural operations. 



Barren as the soil appears in its present dried condition, it has the 

 capacity for production of luxuriant crops of corn, barley, cabbage, onions, 

 potatoes, and watermelons where water can be furnished, as the garden at 

 old Fort Goodwin proves, and as the Mexican Pueblo Viejo, some twenty 

 miles further up the river, amply confirms. 



Leaving here an altitude of less than 3,000 feet, we again begin the 

 ascent over a rolling country, and reach some twenty miles to the south an 

 altitude of A, 833 feet at New Camp Grant. North of this, Mount Graham 

 rises out of the plain, and attains an altitude of 10,357 feet. It is stated by 

 Mr. Gilbert* to be made up on its northeastern face of gneissic rocks and a 

 syenite, the great mass being probably metamorphic. As a single isolated 

 centre, it presented more novelties than any other spot visited by us. Picea 

 Engelrnanniwas found even so far south. I have elsewhere called attention 

 to the number of more northern forms that we obtained from near its summit. 



* Vol. iii, 509, Wheeler's Report. 



