332 DIVISION II. ARTICULATED ANIMALS.—CLASS IV. INSECTA. 
fleshy tubercle on the upper part of the last ring. It feeds on the mulberry. 
Before spinning, it fasts for thirty-six hours, voids all its excrements, becomes 
soft and flaccid, and secks a suitable place for the construction of its cocoon. 
Two or three days are occupied in this work; and the thread is stated by 
Count Dandolo to be sometimes six hundred and twenty-five yards in length. 
The worm then changes to a chrysalis, and, after remaining twenty days, 
the moth comes out, forcing its way through the cocoon. The males first 
appear, and are very brisk in their motions, but do not fly, at least in cold 
climates. They live but a few days, and the females perish also as soon as 
they have deposited their eggs. The eggs are attached, often to the number 
of five hundred or more, by means of a gummy substance, and hatch in the 
ensuing spring. The successful rearing of silk-worms is a distinct art, and 
requires peculiar attention. They are subject to a variety of maladies. 
In many places it is usual to import the eges from some district that has 
acquired a reputation for their production. These are packed like grain, 
and are chosen much in the same manner. The eggs are in many places 
hatched by the human body. The silk is contained, in the form of a fluid, 
resembling varnish, in long, cylindrical sacks, many times the length of the 
animal, and capable of being unfolded by immersion in water. The fluid 
is easily forced out, and advantage is sometimes taken of this circumstance 
to procure threads much coarser than usual, which are extremely strong, and 
impermeable to water. 
According to P. Mailla (“L’//istoire générale de la Chine”), the vir- 
tues of the Silk-worm were first discovered in that ancient empire. He 
remarks, — 
“The Emperor Hoang-ti, who lived two thousand six hundred years be- 
fore our era, wished that Si-ling-chi, his wife, should contribute to the hap- 
piness of his people; he charged her to study the Silk-worm, and to try to 
utilize its threads. Si-ling-chi caused a great quantity of these insects to be 
collected, which she fed herself in a place destined exclusively for the pur- 
pose; she not only discovered the means of rearing them, but, still further, 
the manner of winding off their silk and of employing it in the manufacture 
of fabrics.” 
Upon this statement, M. Duhalde, in his “ Description de la Chine,” 
thus comments : — 
“Up to the time of this queen (Si-ling-chi), when the country was only 
lately cleared and brought into cultivation, the people employed the skins of 
animals as clothes. But these skins were no longer sufficient for the multi- 
tude of the inhabitants; necessity made them industrious; they applied 
themselves to the manufacture of cloth wherewith to cover themselves. 
But it was to this princess that they owed the useful invention of silk stuffs. 
