cessary to make it fit for
the ends it attains at the hand of man.
The mulberry silkworm can readily be bred in confinement. The eggs are
easily gathered and preserved, and are so readily kept that they may be
sent the world about. At a given temperature they with infrequent
failures hatch; and if sufficiently fed with the fresh leaves of the
mulberry, will in a short time attain to as perfect a development as
though they grew, not in close rooms, but in the open conditions of the
trees. When of adult size, the grubs proceed to spin themselves in,
forming a thick cocoon composed of threads of a material which, though
as soft as paste when emitted from the body, hardens so as to form a
strong and even thread. If the insect be allowed to remain for a
sufficient time in the cradle which it has spun for its second birth,
the body within the chrysalis case will proceed in a manner to
dissolve; and in the milky fluid thus produced, where only faint traces
of its former state remain, the beautiful image or perfect form will
arise. In the economic use of the creature, however, except as far as a
supply of eggs may be desired, it is necessary to prevent the
completion of its development; for in escaping from the chrysalis case,
the butterfly cuts many of the delicate threads, so that the silk is
made unserviceable. It is necessary to wind it off before the insect
escapes. In this part of the work we notice the most perfect adaptation
of the creature to the needs of man. While the silk threads from the
cocoons of other species which might prove of value cannot be easily
reeled off, those of the silkworm, when placed in hot water, readily
separate, and can be gathered in a condition for spinning. Thus, while
some success has been attained by carding the cocoons of other species,
thereby making a fibre which has a certain utility, the silkworm alone
yields material fitted for delicate fabrics.
[Illustration: The Farmer's Apiary]
At the present time in Europe, Asia, and America there are probably not
far from ten million people who depend in large measure upon the
product of the silkworm for their livelihood. Although the product of
their industry and that of the insects combined is not nearly as
indispensable to man as those which are won from the hair of animals or
the fibres of plants--for silk is a luxury rather than a necessity--the
value of the work done by these humble creatures is greater than that
effected by the larg
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