DESEET VEGETATION. 
127 
ments necessary for determining the masses and positions of the several 
stratigraphic members with a degree of accuracy not materially less than 
could be obtained by studying them upon their own ground. 
A spectacle of this kind is most impressive to the geologist. It brings 
into one view the co-ordinated results of observations made laboriously by 
months of travel and inspection in a very broad and rugged field. The 
great distances through which the eye can reach, the aspect of cliffs tower- 
ing above and beyond cliffs, the great cumulative altitude thus attained, the 
immensity of the masses revealed, the boldness of form, the distinctness of 
the lines of stratification, and especially the brilliant coloring, subdued in- 
deed, but also refined by the haze, give to the scene a grandeur which has 
few parallels. 
But we turn our backs upon it, and pursue our way, pausing anon to 
look at it with a reverent enthusiasm. The daylight discloses the western 
Kaibab wall upon our left, only five or six miles distant, and our course 
changes from southeast to south parallel to its front. Already we feel the 
influences of its long spurs sweeping outward and dying away in the desert 
platform, and the trail becomes more hilly. Once or twice it takes us down 
into ravines which are the continuations of the great chasms which cut it to 
its base and recede far into its mass, winding out of sight in profound depths. 
Vegetation has made its appearance all around us, not abundantly, indeed, 
but sufficiently to contrast with the desolation behind us. Upon the crest 
of the plateau we can see the giant pines and spruces, and we covet their 
luxurious shade. Nearer, on either hand, are pinons and cedars, mountain 
mahogany and mesquite, with many low forms of desert shrubbery. Many 
species of cactus are seen, the most abundant of which are the opuntias, or 
prickly pears. Of these there are four or five very common species. A 
large cactus “orchard” in blossom is a very beautiful sight, displaying 
flowers which, for beauty of form and richness of color, are seldom sur- 
passed by the choicer gems of the conservatory. Nor is it less attractive 
when in the fruit, for it yields a multitude of purple “ pears,” which are 
very juicy and refreshing, and by no means contemptible in flavor. There 
is another form of cactus not likely to be forgotten by anybody who has 
once seen it, and which is very common on the Kauab desert. It is a stout 
