32 EUCALYPTS CULTIVATED IN THE UNITED STATES. 
The species suited to particular localities or conditions may be ascer- 
tained by reference to pages that follow. Those that grow in Australia 
on the uplands and in other dry situations can be used here to cover 
similar regions. In the Southwest there are large areas of hilly coun- 
try, of little or no use for other purposes, that might be transformed 
into useful forests by covering them with these trees. This covering 
of the hills with forests will not only furnish shade, a source of honey, 
and a supply of fuel and timber, but will prevent the too rapid run- 
off of rain water, which results in the cutting and washing of hillsides 
and in other forms of damage below. On this point Mr. Cooper, in a 
letter to the writer dated June 18, 1900, says: 
South of where I live, about one-eighth of a mile, is a steep hillside. I noticed 
during my residence the first years that heavy rains washed down the soil, all the 
rain running off. I planted Eucalyptus trees on this hillside, about 4 feet apart. 
When these trees had four or five years of growth we had a tremendous rain storm, 
14 inches of rain falling in four days. Nearly all this water was held by the trees, 
practically none running off. There is always more moisture in the soil near these 
trees than some distance off. There is no question as to the great importance of hay- 
ing our mountain sides well wooded with trees and bushes to preserve the rain for 
the benefit of the valley below. 
The Eucalypts can be utilized as a forest cover for mountains as 
well as hillsides. Several species grow naturally upon the mountains 
of Australia. These will serve as a covering for bare mountain sides 
in the Southwest, and the writer believes that they would prove quite 
valuable for recovering those that have been denuded of their natural 
forests by fire. The rapid-growing species, less resistant to frost, 
could be planted on the lower parts of mountains, and the somewhat 
slower-growing, more hardy ones farther up the mountain sides. 
Those adapted to alpine situations may be planted to a height of from 
4,000 to 6,000 feet. 
Lowlands, too, may be covered with Eucalypts. In Australia several 
species grow naturally in swamps or other low situations. These may 
be utilized for covering the lowlands in:warm regions in other parts 
of the world, thus reducing the amount of the stagnant water, and in 
other ways rendering such localities more agreeable. 
Judging from observations made during the past few years (the most 
trying years upon vegetation that have been experienced in the South- 
west since it was settled), the writer believes that much of the tree- 
less desert region might be forested with Eucalypts. At the close of 
the season of 1900, the driest one of which the Weather Bureau has a 
record, trees of several species were observed growing without irriga- 
tion in southern Arizona, and some of them had not been irrigated 
for many years. Trees of the Red Gum (/ucalyptus rostrata), the 
Sugar Gum (£2 corynocalyx), and of EF. tereticornis, growing in a neg- 
lected tract under desert conditions where the ground water was about 
100 feet below the surface, endured the above trying summer. ‘This 
