of service to those who which to secure sound eggs:

[Illustration]

For each ounce of eggs to be produced, about three-quarters of a pound of
fresh cocoons from the finest and firmest in the lot should be chosen.
These should be strung in sets upon a thread, care being taken not to
pierce the chrysalis, and the strings hung in a cool, darkened room. The
moths generally emerge from the cocoons early in the morning, and will be
seen crawling about over these, the males being noticeable by their
smaller abdomens, more robust antennae, and by their greater activity. The
moths should be placed, regardless of sex, on a table, where they will
soon find their mates and couple. As soon as formed, the couples should
be removed to another table, that they may not be disturbed by the
flutterings of the single moths.

There should be prepared for each ounce of eggs to be produced, about
one hundred small bags of fine muslin, made in the following manner: Cut
the cloth in pieces 3x6 inches. Then fold one end over so as to leave a
single edge of about three-quarters of an inch, as shown in the
accompanying cut. This should be sewn up into a bag with the upper end
open, and then turned inside out, so that the seams will cause the sides
to bulge. Thus completed they are called "cells." The cells should be
strung on a cord stretched across the room.

The moths couple as a rule about eight o'clock in the morning. About four
in the afternoon they should be separated by taking them by the wings and
drawing them gently apart. Each female should now be placed by herself in
a cell, which is then closed by a pin as shown in the figure. Here she
will lay her eggs and in due time die. The males may as a rule be thrown
away, but it is wise to keep a few of the more active ones, in case there
should be a superabundance of females the following day.

When the females have finished laying their eggs, which operation
occupies about thirty-six hours, they are ready to be shipped to this
office. The cells, with their inclosed moths and eggs, should be placed
in a strong box of wood or tin, being packed in such a manner that they
will not be crushed, and mailed to the entomologist at the department. By
using the inclosed return penalty slip, payment of postage may be
avoided. The name of the sender should be placed in each box. The moths,
as soon as received, will be examined microscopically, and the eggs of
those which are found to be free from di