SILK-WOKM. 315 



and down, and crossing to every side. It soon con- 

 fined its movements to a very contracted space, and, 

 by degrees, entirely surrounded itself with silk ; and 

 the remainder of its operations became invisible, 

 though these may be understood from examining the 

 work after it is finished. In order to complete the 

 structure, it must draw out of the gum-bag a more 

 delicate silk, and then with a stronger gum bind all 

 the inner threads over one another. 



" Here, then, are three coverings entirely differ- 

 ent, which afford a succession of shelter. The outer 

 loose silk, or floss, is for keeping off the rain ; the 

 fine silk in the middle prevents the wind from caus- 

 ing injury ; and the glued silk, which composes the 

 tapestry of the chamber where the insect lodges, re- 

 pels both air and water, and prevents the intrusion 

 of cold. 



" After building her cocoon, she divests herself oS 

 her fourth skin, and is transformed into a chrysalis, 

 and subsequently into a moth (Bombyx mori), when, 

 without saw or centre-bit, she makes her way through 

 the shell, the silk, and the floss ; for the Being who 

 teaches her how to build herself a place of rest, where 

 the delicate limbs of the moth may be formed with 

 out interruption, instructs her likewise how to open 

 a passage for escape. 



" The cocoon is like a pigeon's egg, and more 

 pointed at one end than the other; and it is remark- 

 able that the caterpillar does not interweave its silk 

 to ards the pointed end, nor apply its glue there as 

 it does in every other part,* by bending itself all 

 around with great pliantness and agility : what is 

 more, she never fails, when her labour is finished, to 

 fix her head opposite to the pointed extremity. The 

 reason of her taking this position is that she has 



* This is denied by recent observers 



t2 



