220 THE INSECT WORLD. 





Department of Ardeche. That country possesses some 1,400 

 manufactories of raw silk, and over 1,200 spinning or weaving works, 

 with more than 100,000 spindles, 40,000 power-looms, and 60,000 

 hand-looms. The imports of silk yarns and pieces amount to 

 close upon ;^i, 7 50,000 per annum in value, and the yearly value 

 of the exports of the same approach ;^9,ooo,ooo. This enormous 

 trade shows how popular this beautiful fabric still is, an estimation 

 that is to be explained by the consistency of the stuff, its smooth- 

 ness, its softness of surface, the manner in which it receives colours, 

 its brightness, fineness, power of reflecting, its rustle, and other 

 qualities. 



The Bombyx mori has, however, nothing alluring in its appear- 

 ance. Other caterpillars of the genus Bo?nbyx have brilliant liveries; 

 they are adorned with spots, blue as sapphires, green as emeralds, red 

 as rubies, but produce threads without brightness and fineness. The 

 humble silkworm, in a white blouse, like a workman, has nothing 

 brilliant in its dress, and yet it gives to the whole world its most 

 beautiful and gorgeous array. The body of the silkworm is composed 

 of thirteen distinct segments. In front are three pairs of articulated 

 legs, which will become later those of the moth. In the middle and 

 towards the posterior i)art, are five i)airsof membranous legs, furnished 

 with a circle of very fine bristles, which assist the animal to hook 

 itself on to leaves and stalks. On the two sides of its body are 

 eighteen stigmata, or respiratory mouths. 



The head of the silkworm is remarkable ; it is scaly, horny, and 

 formed of one single piece. The mouth is provided with six small 

 articulated pieces. Below is a simple blade, the upper lip, having in 

 its middle a hollow, into which the animal causes the edge of the 

 leaf it is gnawing to enter, and holds it thus without any exertion. 

 Underneath the lip are inserted t\YO large jaws, which cut the leaf as 

 a pair of scissors. Underneath, some weaker jaws divide the 

 fragments, and a little organ, articulated on to each jaw, that is tO| 

 say, a palpus, pushes them back towards the mouth, and prevents thej 

 smallest particle of the leaf from falling. And lastly, in the space; 

 comprised between the two jaws, is an under-lip, which completely 

 closes the mouth below. At the extremity of this piece may be seen 

 a little prolongation, a sort of papilla, pierced with a hole, which 

 the orifice that gives issue to the silky thread. 



The organs which serve for the elaboration and emission of the 

 silk have a peculiar interest for us. If we dissect a silkwonn undei 

 water, we succeed, sooner or later, after having removed the outei 

 parts, in laying bare a double apparatus, placed along the two sidi 



