the proportions of a tree and forms
thick forests over an area of many miles. The Spanish bayonet, with
its long stalk of white, waxy blossoms, presents a very beautiful
appearance, as do also the young specimens of the tree yucca.

At rare intervals, once perhaps in many years, there is an unusual
amount of rainfall in the spring, and in a few weeks the desert
becomes transformed as if by magic. Seeds germinate, the presence
of which one would never have suspected in the drier weather. In
an incredibly short time the long gravelly or sandy slopes about
the bases of the mountains are covered with a veritable carpet of
green, yellow, and red. The sand verbena, the evening primrose,
baby blue-eyes, and different kinds of lilies grow so thickly in
places that every footstep crushes them.

[Illustration: FIG. 90.--YOUNG YUCCAS IN BLOOM]

But in a few short days the beauty has disappeared. The seeds mature
speedily and drop into the sand. A hot wind withers the stems and
leaves and blows them away; drifting sands take the place of the
rich carpet. How readily these plants have adapted themselves to
the brief period in which life is possible!

Thus it is that this vast region about the lower Colorado, although so
dry and hot, and at first sight apparently so unfitted for sustaining
life, nevertheless supports its share. Many of the plant forms have
assumed strange and monstrous shapes in their efforts to withstand
the hard conditions in the struggle for existence, while others simply
lie in waiting, sleeping during the long dry year, but ready to
spring into life when the favorable showers come, as they sometimes
do.

THE PONY EXPRESS

Although it is only a little more than fifty years since the discovery
of gold was made and the rapid settlement of the West began, what a
change has come over this great region! It was at first supposed to
be impossible to connect the growing settlements upon the Pacific
with the East by anything more than a wagon road, and those who
advocated the building of a railroad were ridiculed. Now the journey
across the continent is made upon smooth steel tracks in comfortable
coaches, for the skill of the engineer has overcome the difficulties
of the desert, the mountain wall, and the canon.

The pioneers who pushed westward from the Mississippi River with
their slow ox-teams took all summer to reach the fertile valleys
of California and Oregon, and considered themselves fortunate if