44 EUCALYPTS CULTIVATED IN THE UNITED STATES. 
water in the ground at their roots; second, their corresponding power 
of giving off fresh from their foliage the water thus taken up by their 
roots; third, the exhalation from their leaves and other parts of vola- 
tile oils, which affect the climate not only directly but by changing 
the oxygen of the atmosphere to ozone; fourth, the purification of 
germ-intested matter by the foliage dropped upon the ground or in 
pools of standing water. From the combined action of these four 
characteristics is seems reasonable to believe that the trees would be 
beneficial to many climates. 
It is not necessary to determine, however, .befure setting Eucalypts, 
whether they have a pronounced beneficial effect upon climate or not. 
They certainly do not injure a climate. They serve so many other 
useful purposes that the question as to their effect upon climate may 
be waived, and the planting of them still go on from other motives. 
The belief that they improve climate has served a useful purpose 
regardless of the facts in the matter. The planting of trees is such a 
desirable thing that it matters little what the motive for planting them 
be, provided they get planted. Eucalypts may confidently be grown 
for a forest cover, for wind-breaks, for shade, for timber, for fuel, 
for the oil and the honey they furnish, and if, at the same time, they 
improve the sanitary condition of the region in which they are grow- 
ing, the reward of the planter will be so much the greater. 
PROPAGATION AND CARE OF EUCALYPTS. 
DIFFICULTIES IN GROWING SEEDLINGS. 
Eucalyptsare less easily propagated in America than most other forest 
trees. This is due in part to the smallness of their seeds and the infer- 
tility of many of them, and in part to the fact that each species 
requires, or at least prefers, certain peculiar climatic conditions. Few 
grow spontaneously in the Southwest yet, and none do so freely. The 
Red Gum and the Blue Gum are occasionally found growing spontane- 
ously from fallen seed, and at Mr. Cooper’s ranch near Santa Barbara 
Red Gum seedlings were seen by the writer in abundance under trees 
in shaded canyons, ana in washes below the trees. (Pl. VIII.) Mr. 
Cooper also pointed out trees about a foot in diameter that had grown 
from volunteer seedlings. Southwest of-Los Angeles, near the ocean, 
where the temperature is even and the atmosphere more humid than 
farther inland, young seedlings often appear in the groves of Blue 
Gums, and this occurs in similar situations in central California, being 
very noticeable on the university campus at Berkeley. On the Min- 
newawa ranch, near Fresno, seedlings of Hucalyptus rudis appear under 
the trees in abundance each spring, and are used by the owner ior 
planting. (PI. VIII, Bs.) 
In some regions species which grow fairly thriftily when once started 
