SILK-WORM.
Reshm ki keeri, • DIIK. I Puttoo purughu, . TEL. Puttoo puchie, . . TAM. I Nar puttoo, . . . . „ Aceording to Pusanias, the Greeks called the silk-worm Ser. The Tibetans call it Darkyi srin, from Srin or Srin-bu, a beetle.
Procopius (De Bello Gallic()) says about A.D. 500-565 certain monks arrived from the (country of the) Indians, and learning that the emperor Justinian had it much at heart that the Romans should no longer buy silk from the Persians, they came to the king and promised that they would so manage about silk that the Romans should not have to purchase the article either frorn the Persians or from any other nation ; for they had lived, they said, a long time in a country where there were many nations of the Indians, and which goes by the name of Serinda.
Theophanes of Byzantium, writing at the end of the 6th century, says : NOW, in the reign of Justinian, a certain Persian exhibited in Byzantium the mode in which (silk) worms are hatched, a thing which the Romans had never known before. This Persian, on coming away from the country of the Seres, had taken away with him the eggs of these worms (concealed) in a walking-stiek, and succeeded in bringing them safely t,o l3yzantium." Diseases of the Silk: worm.—That most frequently met with is known by the name of pattes noires or poivre in France. M. de Quatrefages proposed to call it the inaladie de la tache, from the spots which appear on the worm when attacked with it. These spots can only be perceived by the aid of a magnifying glass, and this circumstance explains why the malady escaped the observation of silk growers in the majority of eases until five or six (lays after the worm had cast its fourth skin. Tho spots exist in all the tissues and organs of the worm, and in its subsequent stages of a chrysalis and moth. In the latter the spots destroy the antennte, tho legs, or a portion of the wings. In the beginning the spot appears under the form of a yellowish matter pervading the whole system ; this matter gradually becomes darker, and is then concentrated into a number of tubercles, which are the spots in question. That such a diseased state should exercise an influence on the quality of tho egg, is not surprising. An infected silk worm may spin its cocoon when the disease is not too far gone, but the insect generally dies, and the body, instead of putrefying, becomes dry and brittle. M. de Quatrefages tried several methods of cure,—first, the hygienic process, which consists in rearing the worms in open sheds instead of close rooms. The leaves of the wild mulberry, not stripped from tho branches, lie found very efficacious. He strongly recommended silk-growers
to rear small lots of worms apart from the others, solely for the purpose of propagating, the species. From his experiments, it appears that the silk worm does not refuse to eat the leaves of the mulberry sprinkled with Peruvian bark, gentian, valerian mustard, ete., and the two latter powders especially would seem to produce good effects. But scraped sugar appeared to be preferable to all other remedies. The worms cat the leaves sprinkled with sugar with extraordinary relish, and experiments with this substance were accord ingly repeated on a larger scale in the establish ment of Augliviel, in the department of the Gard, where one of the silk sheds, fitted up for twenty-seven trays, was reduced by disease to four. The worms of these were transferred to another shed, and divided into four lots ; the first was fed in the common way, the second with moistened leaves, the third with sugared leaves, and the fourth was subjected to a rigorous absten tion of food for seventy-five hours, and then fed chiefly with sugared leaves. At the end of twenty four hours several worms of the latter lot began to spin, and made several small and imperfect cocoons on the tray. The other worms began t,o shrivel up and diminish in size, but on receiving the sugared leaves they speedily rallied, and many of them spun their cocoons. The worms fed with moistened leaves fared very badly, and very few of them spun cocoons. Those fed in the common way presented nothing remarkable, and yielded a certain quantity of cocoons ; but those fed with sugared leaves throve well, and spun their cocoons sooner then the others. The quantities of silk yielded by these four lots were respectively :— 1st lot, 210 grammes ; 2d lot, nought ; 3d lot, 392 grammes, and of a superior quality ; 4th lot, 152 grammes. One great fact was put beyond a doubt, viz. that medicine may be administered to silk-worms in the same way as it is administered to cattle and poultry.
Mr. Thomas Wardle, F.C.S., tells us in the Society of Arts Journal, 9th May 1879, that the silk producing insects belong to the order Lepidoptera, and are membersof two families, Itombyeidai and Saturniblx. All the Saturniithe are silk spinners, but not all tho ltombychlm. The British Museum Catalogue contains the names of 291 species of Saturniblie. The Bomby chile are loss numerous. The position of these two families in the great system of classification of the animal kingdom may bo thus shown :—