1909 DIRECT BENEFITS DERIVED FROM INSECTS. 
same time cheap and durable dress, such as this silk furnishes, is much 
wanted. The durability of this silk is indeed astonishing. After constant 
use for nine or ten years it does not show any signs of decay. These 
insects are thought by the natives of so much consequence, that they guard 
them by day to preserve them from crows and other birds, and by night 
from the bats. The Arindy silk-worm (Saturnia Cynthia Drury), which 
feeds solely on the leaves of the Palma Christi, produces remarkably soft 
cocoons, the silk of which is so delicate and flossy, that it is impracticable 
to wind it off: it is, therefore, spun like cotton; and the thread thus 
manufactured is woven into a coarse kind of white cloth of a loose texture, 
but of still more incredible durability than the last, the life of one person 
being seldom sufficient to wear out a garment made of it. It is used not 
only for clothing, but for packing fine cloths, &c. Some manufacturers in 
England to whom the silk was shown seemed to think that it could be 
made here into shawls equal to any received from India, A moth allied 
to this last species, but distinct, has been described and figured by Colonel 
Sykes, who met with its leather-like cocoons composed of silk so strong, 
that a single filament supported a weight of 198 grains, in that part of the 
Deccan in India lying between the sources and junction of the Béma and 
Mota Mola rivers. These cocoons are called kolésurra by the Mahrattas, 
who use them cut into thongs, which are more durable than leather for 
binding the matchlock barrel to the stock; but as far as Colonel Sykes 
could ascertain, no use is made of the silk in Western India, though there 
can be little doubt that it might be advantageously produced, as the cater- 
pillars which spin it feed indiscriminately on the Teak tree ( Z'ectona grandis), 
the Mulberry (Morus indica), the Bor (Zizyphus Tujubey, and the Osana 
(Terminalia alata glabra) 3 
Other species, as may be inferred from an extract of a letter given in 
Young’s Annals of Agriculture*, are known in China, and have been intro- 
duced into India. “We have obtained,” says the writer, ‘a monthly 
silk-worm from China, which I have reared with my own hands, and in 
twenty-five days have had the cocoons in my basins, and by the twenty- 
ninth or thirty-first day a new progeny feeding in my trays. This makes 
it a mine to whoever would undertake the cultivation of it.” 
Whether it will ever be expedient to attempt the breeding of the larvae 
of any European moths, as Catocala pacta, sponsa, &c. proposed with this 
view by Fabricius *, seems doubtful, though certainly many of them afford 
a very strong silk, and might be readily propagated ; and I haye now in 
my possession some thread more like cotton than silk spun by the larva 
of a moth, which when I was a very young entomologist I observed (if 
my memory does not deceive me) upon the HZuonymus, and from the twigs 
of which (not the cocoon) Iunwound it, It is even asserted that in 
Germany a manufacture of silk from the cocoons of the emperor moth 
(Saturnia Pavonia major) was at one time established.* There seems no 
question, however, that silk might be advantageously derived from many 
native silk-worms in America. An account is given in the Philosophical 
Transactions of one found there, whose cocoon is not only heavier and 
more productive of silk than that of the common kind, but is so much 
1 Trans. Royal Asiat. Soc. 1884. yol. iii, 2 xxiii, 235. 
5 Vorlesungen, 325. 4 Latr. Hist. Nat. xiv. 150. 
