one of the most valuable
articles of clothing. Blot out the silk worm, and we should remove one
of the most important sources of national wealth, the annual revenue
from the silk trade of the world amounting to $254,500,000.

[Illustration: 49. Eight-spotted Alypia and Larva.]

[Illustration: 50. Eudryas grata.]

[Illustration: 51. Larva of Psychomorpha.]

[Illustration: 52. American Procris and Young.]

[Illustration: 53. Larvae of American Procris.]

Silk culture is rapidly assuming importance in California, and though
the Chinese silk worm has not been successfully cultivated in the
Eastern States, yet the American silk worm, Teleas Polyphemus (see
frontispiece, male; Fig. 54, larva; 55, pupa; 56, cocoon), can, we are
assured by Mr. Trouvelot, be made a source of profit.

This is a splendid member of the group of which the gigantic Attacus
Atlas of China is a type. It is a large, fawn colored moth with a tawny
tinge; the caterpillar is pale green, and is of the size indicated in
the cut. Mr. Trouvelot says that of the several kinds of silk worms, the
larva of the present species alone deserves attention. The cocoons of
Platysamia Cecropia may be rendered of some commercial value, as the
silk can be carded, but the chief objection is the difficulty of raising
the larva.

"The Polyphemus worm spins a strong, dense, oval cocoon, which is closed
at each end, while the silk has a very strong and glossy fibre." Mr.
Trouvelot, from whose interesting account in the first volume of the
"American Naturalist" we quote, says that in 1865 "not less than a
million could be seen feeding in the open air upon bushes covered with a
net; five acres of woodland were swarming with caterpillar life." The
bushes were scrub oaks, the worms being protected by a net. After
meeting with such great success Mr. Trouvelot lost all his worms by
pebrine, the germs being imported in eggs received from Japan through M.
Guerin-Meneville of Paris. Enough, however, was done to prove that silk
raising can be carried on profitably, when due precautions are taken, as
far north as Boston. As this moth extends to the tropics, it can be
reared with greater facility southwards. The cocoon is strong and dense,
and closed at each end, so that the thread is continuous, while the silk
has a very strong and glossy fibre.

[Illustration: 54. American Silk Worm.]

Next in value to the American silk worm, is the Ailanthus silk worm
(Samia Cynthia) a specie