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THE AMERICAN SILK WORM. 31 
beautiful lustre. Every one is familiar with the beautiful 
and delicate fabric made from the fibres spun by that 
crawling repulsive creature, the silk worm. 
< Our country alone has eight or ten species of silk 
worms. Two of these, Callosamia Promethea and C. an- 
gulifera, feed on the lilac and wild cherry. They spin a 
small elongate cocoon of so very dense texture and so 
strongly gummed, that I have failed in all my attempts to 
reel the silk from the cocoon. These cocoons resem- 
ble very much those of Samia Cynthia, or the Ailan- 
thus Silk Worm, recently introduced into Europe from 
China, but the cocoon is of a looser texture. Platysamia 
Euryale, P. Columbia and P. Cecropia feed upon many 
different species of plants} they make a large cocoon, 
within which is another cocoon, or inner layer, of an oval 
form ; but as the larva in spinning the cocoon, leaves one 
end open for the exit of the moth, this prevents the reeling 
of a continuous thread. The silk, though quite strong, has 
not much brilliancy, and the worm is too delicate to be 
raised in large numbers. 
The cabanas of Tropxa Luna, the magnificent green 
moth with the long tail-like expansion of the hind wings, 
feeds upon. the cat; sycamore and other trees, and spins 
an oval cocoon, which however is so frail and thin, and 
the fibre so weak, that itis impossible to reel it. 
_ Practically, however, the larva of Telea Polyphemus is 
the only species that deserves attention. The cocoons of 
Platysamia Cecropia may be rendefed of some commercial 
value, as the silk can be carded, but the chief objection as 
stated above, is the difficulty of raising the larva. The Poly- 
phemus worm spins a strong, dense, oval cocoon, which is 
closed at each end, while the silk has a very strong and 
glossy fibre. 
