THE SILKWORM. 



511 



time it seems to sleep again ; and, when it 

 awakes, it again changes its clothing, and 

 continues feeding as before. When it has 

 thus taken a sufficiency of food, and its parts 

 are disposed for assuming the aurelia form, 

 the animal forsakes, for the last time, all food 

 and society, and prepares itself a retreat to 

 defend it from external injuries, while it is 

 seemingly deprived of life and motion. 



This retreat is no other than its cone, or ball 

 of silk, which Nature has taught it to compose 

 with great art ; and within which it buries 

 itself, till it assumes its winged form. This 

 cone or ball is spun from little longish kinds 

 of bags that lie above the intestines, and are 

 filled with a gummy fluid, of a marigold col- 

 our. This is the substance of which the 

 threads are formed ; and the little animal is 

 furnished with a surprising apparatus for 

 spinning it to the degree of fineness which its 

 occasions may require. This instrument in 

 some measure resembles a wire-drawer's 

 machine, in which gold or silver threads are 

 drawn to any degree of minuteness ; and 

 through this the animal draws its thread with 

 great assiduity. As every thread proceeds 

 from two gum-bags, it is probable that each 

 supplies its own ; which however, are united, 

 as they proceed from the animal's body. If 

 we examine the thread with a microscope, it 

 will be found that it is flatted on one side, and 

 grooved along its length : 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 silkworm seeks out some convenient place 

 to erect its cell, without any obstruction. 

 When it has found a leaf, or a chink fitted to 

 its purpose, it begins to wreathe 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 ap- 

 pears, indeed, no order or contrivance in the 

 disposal of its first threads ; they are by no 

 means laid artfully over each other, but are 

 thrown out at random, to serve as an external 

 shelter against rain ; for nature having ap- 

 pointed 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 

 externally of a kind of rough cotton-like sub- 

 stance, which is called floss ; within, the 

 thread is more distinct and even ; and next the 

 body of the aurelia, 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 

 be found about three hundred yards long ; and 

 so very fine, that eight or ten of them are 

 generally rolled oft* into one by the manufac- 

 turers. The cone, when completed, is in form 

 like a pigeon's egg, and more pointed at one 

 end than the other: at the smaller end, the 

 head of the aurelia is generally found : and 

 this is the place that the insect, when con- 

 verted into a moth, is generally seen to burst 

 through. 



It is generally a fortnight or three weeks 

 before the aurelia is changed into a moth; 

 but no sooner is the winged insect completely 

 formed, than having divested itself of its aurelia 

 skin, it prepares to burst through its cone, or 

 outward prison : for this purpose it extends its 

 head towards the point of the cone, butts with 

 its eyes, which are rough, against the lining 

 of its cell, wears it away, and at last pushes 

 forward, through a passage which is small at 

 first, but which enlarges as the animal in- 

 creases its efforts for emancipation ; while the 

 tattered remnants of its aurelia skin lie in con- 

 fusion within the cone, like a bundle of dirty 

 linen. 



The animal, when thus set free from its 

 double confinement, appears exhausted with 

 fatigue, and seems produced for no other pur- 

 pose but to transmit a future brood. It neither 

 flies nor eats ; the male only seeking the fe- 

 male, whose eggs he impregnates; and their 

 union continues for four days, without inter- 

 ruption. The male dies immediately after 

 separation from his mate ; and she survives 

 him only till she has laid her eggs, which are 

 not hatched into worms till the ensuing spring. 



However, there are few of these animals 

 suffered to come to a state of maturity ; for as 

 their bursting through the cone destroys the 

 silk the manufacturers take care to kill the 

 aurelia, by exposing it to the sun, before the 

 moth comes to perfection. This done, they 

 take off the floss, and throw the cones into 

 warm water, stirring them till the first thread 

 offers them a clue for winding all off. They 

 generally take eight of the silken threads 

 together ; the cones being still kept under 

 water, till a proper quantity of the silk is 

 wound off: however, they do not take all; 

 for the latter parts grow weak, and are of a bad 

 colour. As to the paper-like substance which 

 remains, some stain it with a variety of colours, 

 to make artificial flowers ; others let it lie in 

 the water, till the glutinous matter which 

 cements it is all dissolved : it is then carded 

 like wool, spun with a wheel, and converted 

 into silk stuffs of an inferior kind. 



