The Washington herald., 1915-08-29

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sumes q nearly transparent pinlish color.
It then commences a search for . place
to attach the lines which form the su-
perstructure of the cocoon in which IT 10
about to enclose itself. Having no sight.
the worm moves restlessly about feeling
every object with which It comes in con
tact, until 1t selects a spinning place.
Once this is done the worm works rapid
ly. exudins nearly foot Of silk minute.
which it winds in short irregular figure
eight loops by waving its head from side
to side. Later the spinner lessons its
pace. producing about six inches Of silk
q minute. The cocoon Is completed in
about three days. though the busy. spin
nrst twenty-four hours.
On the completion Of the cocoon. the
worm IL little more than an inch long
and by a final molt within the cocoon
becomes the chrysalis with the four future
wings Of the moth folded over its breast
with six slender legs and two antennae
After an incubation period Of from two
to three weeks. the chrysalis stirs to life.
bursts its inner shell and the now fully
developed moth elects liquid. strongly
alkaline, against the end Of the tough.
gummy cocoon. This softens the lining 20
that the moth Is able to break and push
aside the restraining threads and emerge
into the outer world.
Incapable Of flight the moth or image,
passes the few days Of its existence With.
IN the space Of less than q foot. It has
no mouth and hence takes no nourish.
ment In contrast to the sightless cater
pillar. however. the moths have eyes and
seek their mates within few hours Of
leaving the cocoon. One moth lays three
or four hundred eggs. at first yellow but
turning gray later.
Professor Crane keeps these eggs over
the winter. not permitting them to be in
. temperature warm enough to hatch un-
~ tAO AAoAOSAiy ouo OS080 IC0vS8 nave 10
veloped 30 there may be foed for the baby
worms.
Only the live cocoons are used COM
mercially for silk. the chrysaHs being
killed by immersion of the cocoon In hot
water or steam. Nearly three thousand
cocoons are required to manufacture Q
pound Cf raw silk.
The effort to change the color of the
natural silk so that dyes viii be unneces
sary has attracted the attention Of biolo.
gists In Japan. China and France, Profes-
sor Crane says. I'VE are too busy with
automobiles in the United States to study
trivial thing like this. however" he de-
clares.
In addition to his successful experiment
in changing the color Of the natural silk,
Professor Crane has discovered cure for
hacherie. one Of the diseases Of silk
worms which Pasteur had striven for
years to curb. The disease strikes the
caterpillars between their twenty fifth and
twenty-eighth day. rendering them sappy
and hfeless and destroying thousands at
q time. Professor Crane has shown that
the only successful treatment Is careful
washing with cold water. He b studying
cures for other silk worm plaques In his
private laboratory. silk manufacturers
have offered substanttal prizes for cures
Tor these malAdies which menace the en-.
tire industry by threatening to wipe out
the stlk worm.
my discovery q. the germ causing
hAcherfe and the treatment was the work
Of thirty yearA. Professor Crane says.
4 conclude that the disease 3 contasIous
AInA a. 49,