18 OX ENTOMOLOGY. 



some measure impenetrable from without, is readily opened from within- ; 

 and when the Moth issues from its pupa case, it easily makes its way 

 out, without either the acid or eye files ascribed to the Silkworm. The 

 elastic silk gives way upon being- pushed from within and, when the 

 insect is fairly out, it shuts again of its own accord like a door with 

 spring hinges ; a circumstance which at first puzzled Roesel not a little, 

 when he saw a fine large Moth in his box, and the cocoon apparently in 

 the same state as when he had put it there. 



The SILK WORM is too well known to require description ; but some 

 particulars relative to the silk, and the early history of this renowned 

 insect may not be considered uninteresting. In ancient times the 

 manufacture of silk was confined to the East Indies and China, where 

 the insects that produce it are indigenous. It was thence brought to 

 Europe in small quantities, and in early times sold at so extravagant a 

 price, that it was deemed too expensive even for royalty. The Emperor 

 Aurelian assigned the expence as a reason for refusing his Empress a 

 robe of silk ; and our own James I., before his accession to the crown 

 of England, had to borrow of the Earl of Mar a pair of silk stockings 

 to appear in before the English Ambassador ; a circumstance which 

 probably led him to promote the cultivation of silk in England. The 

 Roman authors were altogether ignorant of its origin, some supposing it 

 to be grown on trees, as hair grows on animals ; others that it was pro- 

 duced by a shell-fish, similar to the muscle which is known to throw out 

 threads, for the purpose of attaching itself to rocks ; others that it was 

 the entrails of a sort of spider, which was fed for four years with paste, 

 and then with the leaves of the green willow, till it burst with fat ; and 

 others that it was the produce of a worm, which built nests of clay and 

 collected wax. The insect was at length spread into Persia, and its eggs 

 were afterwards, at the instance of the Emperor Justinian, concealed in 

 hollow canes by two monks, and conveyed to the Isle of Cos. This em- 

 peror, in the sixth century, caused them to be introduced into Constant!, 

 nople, and made an object of public utility. They were thence suc- 

 cessively cultivated in Greece, in Arabia, in Spain, in Italy, in France 

 and in all places where any hope could be indulged of their succeeding. 



In America, the culture of the Silk-worm was introduced into Virginia 

 in the time of James I. who himself composed a book of instructions on 

 the subject, and caused mulberry-trees and Silk-worm's eggs to be sent to 

 the colony. In Georgia also, lands were granted, on condition. of plant- 

 ing one hundred white mulberry-trees on every ten acres of cleared 

 land. The growth of the Silk-worm has also been tried, but with no 

 great success in this country. Evelyn computed that one mulberry-tree 

 would feed as many Silk-worms annually, as would produce seven 

 pounds of silk. According to that estimate, says Barham, the 2000 

 trees already planted in Chelsea Park, (which take up one third of it) ; 

 will make 14,0001bs. weight of silk ; to be commonly worth but 20s. a 

 pound, those trees must make ^14,000 per annum. During the last 



