begins with the incubation
period. Then follows the rearing. Last is the period in which the
caterpillars mount the little straw stacks provided for them in order
that they may wind themselves into cocoons. I do not enter into the
technics of the retardation and stimulation of seed in order to delay
or to hasten the hatch according to the movements of the market.
Hydrochloric and sulphuric-acid baths and electricity are used as
stimulants; storage in "wind holes" is practised to defer hatching.

Cocoons are reckoned both by the _kwan_ of 8-1/4 lbs. and by the
_koku_ of approximately 5 bushels. The cocoon production in 1918
worked out at about 16-1/2 bushels per acre of mulberry or 18 bushels
per family engaged in sericulture. About 34 million bushels of cocoons
are produced. In 1919 the production was 270,800,000 kilos. The
average production of a _tambu_ of mulberry field was 1.356 _koku_. In
1919 a _koku_ was worth on the average 106.81 yen (including double
and waste cocoons). The cost of producing cocoons rose from 4.105 yen
per _kwamme_ in 1916 to 11.284 yen in 1920. The daily wages of
labourers employed by the farmers rose from 62 sen for men and 47 sen
for women in 1910 to 1 yen 93 sen for men and 1 yen 44 sen for women
in 1920. With the slump, the price of cocoons fell below the cost of
production and there was trouble in several districts when wages were
due. The labourers engaged for the silk seasons of 1916 numbered
341,577, of whom 30,000 came from other than their employers'
prefectures. These people migrate from the early to the late districts
and so manage to provide themselves with work during a considerable
period. As many as 5-1/2 per cent, of the persons engaged in the
industry are labourers. Many employment agencies are engaged in
supplying labour.

It has been estimated that the labour of 19.8 persons (200 per
hectare) is needed for a _tambu_ of mulberry field. The silkworms
hatched from a card of eggs (laid by 100 moths) are supposed to call
for the labour of 49.2 persons (1,456 per kilo, 2.204 lbs.)

The production of _cocoons_ rose from 0.866 _koku_ per card in 1914 to
1.105 in 1918, or from 4,412,000 to 6,832,000.

More than three-quarters of the raw silk produced used to be exported.
Now, with the increase of factories in Japan (the figures are for
1918), only 67 per cent, goes abroad, the bulk of it to the United
States, which obtained from Japan, in 1917-18, 75 per cent., and in
1919, i