The San Francisco call., 1910-06-19

duction of silk soon became an industry
of Importance in Turkey, Greece and
Italy, and later in France, Spain and
Portugal. For centuries the orientals
carefully guarded their monopoly of
silk production The story of how a
monk carried the eggs of the insect to
Europe in a hollow cane is well known
and seems to contain no elements OF
improbability. Japan is now one of
the worlds leading silk producing
countries, and supplies about half of
the importations into the United States.
The total value of the worlds annual
production of raw silk is not known,
but runs into the hundreds of millions
of dollars. The United States alone
imports raw silks to the value of be-
tween $40.000.000 and $4,000. 900 every
year. For more than a century efforts
were made, with occasional intermis-
sionS, to place the rearing of silkwOrmS
for the production Of cocoons upon a
paying basis in this country; but it has
been found to be quite impossible to
compete with the cheap labor of the
orient and the south of Europe. For
years congress appropriated $4,000 an
nually for the purchase of cocoons, so
that sericulturists might have market
for their production until the infant
industry could be established. 1t was
found that it was not likely ever to
outgrow it's infancy, and the last ses-
sion of congress failed to pass the usual
appropriation, bringing experiments in
sericulture to an abrupt but not pre-
mature end.
The life history of the silkworm is
an interesting example of insect meta
morphosis. The eggs are laid in June
Tin countries having a climate similar
to that of our own southern states),
and in this state the winter months
are passed. In April the eggs hatch
into larvae. which grow rapidly. casting
their skins four times in as many
weeks and feeding voraciQusly upon
the leaves of the mulberry tree. When
five weeks old the matured caterpillar,
or "silkworm" begins to spin the
cocoon, consuming three days in the
process. Eighteen days are passed in
the chrysalis stage in the interior of
the cocoon, when the natural moth
breaks the fibers and emerges, it's life
cycle complete. About the last of June
1t lays its eggs, and its mission of re-
production then being accomplished it
noon dies.
The cocoons are the commercially
valuable product of the sil<worm. These
are practically ruined if the moth is
permitted to emerge, the fibers being
broken into lengths so short as to be
of little worth. So the cocoons are
placed in ovens and heated sufficiently
to kill the chrysalis. The hbers are then
carefully reeled in unbroken lengths.
several being spun together to give the
product the requisite strength
Although the profitable production of
silk cocoons appears to be impossible
on a commercially important scale in
the United States, yet the weaving of
silks and the manufacture of silk floss
and similar products constitute great
and growing industry, the perfection of
American machinery and the efficiency
of American workmen more than COM
pensating for the higher cost of labor
in this country, while the finished prodA
ucts are equal or superior in quality to
those of any other country.
An insect benefactor of the human
race. with which most Americans ont
side of the San Joaquin Valley of Cali
fornia are unfamiliar is the fig wasp.
or. to give it its scientific name. the
Blastophaga grossorum, without which
the commercial production of dried figs
would be impossible.
The fig is a peculiar fruit, consisting
simply of receptacle for the flowers.
At the apex of this receptacle is a small
orifice, giving passage from the ex-
terror to the very heart of the fruit.
The varieties of figs eaten fresh contain
neither staminate nor pistiIlate flowers,
but what are called mule" flowers,
which are imperfect staminate bios
sons The fruit natures without the
Intervention of insect agency, but the
seeds are hollow and infertile.
But the Smyrna fig, the only variety