THE SILK-WORM. 80 



from hence we may infer, that it is doubled just 

 upon leaving the body, and that the two threads 

 stick to each other by that gummy quality of 

 which they are possessed. Previous to spinning 

 its web, the silk-worm seeks out some conve- 

 nient place to erect its cell, without any obstruc- 

 tion. When it has found a leaf, or a chink, fitted 

 to its purpose, it begins to writhe its head in 

 every direction, and fastens its thread on every 

 side to the sides of its retreat. Though all its 

 first essays seem perfectly confused, yet they are 

 not altogether without design : there appears, in- 

 deed, no order or contrivance in the disposal of 

 its first threads ; they are by no means laid art- 

 fully over each other, but are thrown out at ran- 

 donij to serve as an external shelter against rain ; 

 for nature having appointed the animal to work 

 upon trees in the open air, its habits remain, 

 though it is brought up in a warm apartment. 



Malpighi pretends to have observed six dif- 

 ferent layers in a single cone of silk : but what 

 may easily be observed is, that it is composed ex- 

 ternally of a kind of rough cotton-like substance, 

 which is called floss ; within, the thread is more 

 distinct and even ; and next the body of the au- 

 relia, the apartment seems lined with a substance 

 of the hardness of paper, but of a much stronger 

 consistence. It must not be supposed, that the 

 thread which goes to compose the cone is rolled 

 round, as we roll a bottom ; on the contrary, it 

 lies upon it in a very irregular manner, and winds 

 off now from one side of the cone, and then from 

 the other. This whole thread, if measured, will 



