392 
LEPIDOPTERA. 
over the edges to form a hollow, within which its cocoon 
is concealed. 
The Luna, Polyphemus, Cecropia, and Promethea moths 
are the only native insects belonging to the genus Attacus 
which are known to me. Their large cocoons, consisting 
entirely of silk, the fibres of which far surpass those of the 
silk-worm in strength, might perhaps be employed in the 
formation of fabrics similar to those manufactured in India 
from the cocoons of the tusseh and arrindy silk-worms, the 
durability of which is such, that a garment of tusseh silk 
“ is scarcely worn out in the lifetime of one person, but 
often descends from mother to daughter ; and even the cov- 
ers of palanquins made of it, though exposed to the influ- 
ence of the weather, last many years.” The method em- , 
ployed by the inhabitants of India for unwinding the cocoons 
of their native silk-worms would probably apply equally 
well to those of our country, which have not yet, that I am 
aware of, been submitted to the same process. It is true 
that experiments, upon a very limited scale, have been made 
with the silk of the Cecropia, which has been carded and 
spun and woven into stockings, that are said to wash like 
lincai. The Rev. Samuel Pullein was among the first to 
attempt to unwind the cocoons of the Cecropia moth, an 
account of which is contained in the “ Philosophical Trans- 
actions of the Royal Society of London,” for the year 1759 * 
Mr. Pullein ascertained that twenty threads of this silk 
twisted together would sustain nearly an ounce more in 
weight than the same number of common silk. Mr. Moses 
Bartram, of Philadelphia, in the year 1767, succeeded in 
bringing up the caterpillars from the eggs of the Cecropia 
moth, and obtained several cocoons from them.f In the 
Paris “Journal des Debats,” of the 23d of July, 1840, is 
an account of the complete success of Mr. Audouin in 
* Vol. LI. p. 54. . „ 
t See “ Transactions of the American Philosophical Society of Philadelphia, 
Vol. I. p. 294. 
