THE STATE ENTOMOLOGIST. 75 



measure similate the leaves of their food-tree, so as to render detection 

 difficult. 



They all, whether native or foreign, need fresh air for their well-being; 

 confinement in rooms and in large numbers together undoubtedly predis- 

 posing to disease. In breeding insects entomologists well know that those 

 species even which best bear confinement, rapidly degenerate in the course 

 of a few generations, and it is a very general law with animal and plant life, 

 that the more it approaches the artificial in contradistinction to the natural, 

 the less vigorous in constitution it becomes. 



It is a little singular that the principal trees which may be used for 

 producing the best silk, namely, the Mulberry, Osage orange and Ailan- 

 thus, are all three of them remarkably free from the attacks of other insects. 



By judicious breeding and selection I believe that the native worms 

 may be improved in their silk-producing qualities, and that the foreign ones 

 may be acclimatized and better adapted to our conditions. 



With this brief prelude I will at once introduce — 



^'The worm that spins the Queen's most costly robe," 

 THE MULBEEEY SILKWOBM—Bombyx ISericaria-] mori, Linn. 



(Lepidoptera Bomb ycida . ) 

 ITS PAST HISTORY. 



Silk seems to have been first manufactured and used as an article of 

 clothing in Asia. At least it was first obtained from thence by the ancients, 

 and the Romans called it, from the name of the country whence it was sup- 

 posed to be brought, Sericum. According to the best records its cultivation 

 commenced in China under the reign of Emperor Houng Ti (Emperor of 

 the Earth), and the Mulberry Silkworm is undoubtedly indigenous to China, 

 where it fed naturally on their wild mulberries. 



The wild worm has yet to be discovered, however, and will doubtless- 

 be found eventually in some of the provinces of China. A wild variety, of 

 small size, living on Mulberry, is said to occur in Java, but it is difficult to 

 say whether it is there indigenous and has always been wild, or whether it 

 has sprung from escaped specimens of the domesticated races.* 



Long before the Christian era, silk was cultivated both in China and 

 India, where a class, whose occupation was to attend to silkworms, appears 

 to have existed from time immemorial, being mentioned in the oldest San- 

 scrit Books.f Its cultivation can be traced back in China to at least 2700 

 B. C. From China it was exported to India, Persia, Arabia, and the whole 

 of Asia. 



♦Maurice Girard. Les Auxiliaries du ver a soie. p. 5. 18&4. 

 tColebrook in Asiatic Researches, V. Gl— quoted by Kirby & Spence. 



