AN ECONOMIC STUDY OF ACACTAS. 23 
this source of tanning material has been recognized for some time; 
the planting of wattles would seem to offer a solution for the difficulty. 
POSSIBILITIES OF GROWTH. 
There are enough trees in California to furnish seed; and the growth 
of individual trees has already demonstrated the fact that tanbark 
acacias should be successful over large areas. On the Pacific coast 
and in the Southwest there are many districts well adapted to tan- 
yielding acacias; and there should be a market not only for the bark 
but for fuel wood after. the bark is removed. Even where isolated 
trees suffer from frost, groves of trees sheltermg each other will not be 
subject to the same damage. Acacia pycnantha, even when small, 
has withstood the winters of Cholame Valley, Monterey County, in a 
district where peach, cherry, and grape crops have been lost through 
late frosts. 
While the amount of rainfall which acacias require seems not to 
have been determined, it is generally assumed that 16 inches a year 
is the minimum for Acacia decurrens. Yet deep-rooted saplings will 
thrive on much less. The reports of the University of California 
show that in the drought years of 1897, 1898, and 1899 acacias of 
the leading tanbark species grew well with rainfall of from 4.8 to 8 
inches. In Los Angeles County young trees set out in the spring of 
1897, and thus subjected to three successive drought seasons, made 
growths of from 4 to 6 feet in height a year, and in 1911 were 2 feet 
in diameter. These and other instances justify the belief that some 
of the best Australian acacias will thrive in America under almost 
desert conditions. If they can be made to supplant large areas of 
chaparral they will maintain a protective covering for the soil and 
produce in addition a profitable crop. 
The increasing demand for tanbark ought to direct attention to 
these drought-enduring wattles. In California the native oak has 
advanced in price from $6 per ton in 1870 to $48 at the present time. 
Bark cutters are now forced to seek the most remote and rugged 
canyons in Mendocino, Humboldt, and Del Norte Counties, and some- 
times carry out the bark on pack mules. In the Mendocino forests, 
once thought to furnish a. practically inexhaustible resource, the 
writer has seen the bark cutters stripping trees only 3 inches in 
diameter. 
California has a large investment in the tanning industry, and 
California leathers are shipped to all parts of the world, so that the 
disappearance of the main source of tannin supply becomes a serious 
problem. | 
It should be possible to produce wattle bark for market on low- 
priced land from cheap home-grown seed. While it is useless to 
