CH. IV.] THE SILKWORM MOTH. 83 



but in stops, going backwards and forwards with a 

 sort of waving motion, which the worm effects by 

 means of its fore feet, while it remains in the in- 

 terior. 



Isnard, an old author, affirms, that the length of 

 the silk of one cocoon, when drawn out, will meas- 

 ure six miles, that is, 10,565 yards; but Count 

 Dandolo says, the probable length is 625 yards ; 

 other authors state it to be about 400 yards ; while 

 Pullein says the average length is 300 yards. The 

 latter author thus writes: ''There is scarcely any 

 thing among the various wonders which the animal 

 creation affords, more admirable than the variety of 

 changes which the silkworm undergoes; but the 

 curious texture of that silken covering with which 

 it surrounds itself, when it arrives at the perfection 

 of its animal life, vastly surpasses what is made by 

 other animals of this class. All the caterpillar kind 

 do, indeed, undergo changes like those of the silk- 

 worm, and the beauty of them in their butterfly 

 state greatly exceeds it; but the covering which 

 they put on before this change into a fly is poor and 

 mean, when compared to that golden tissue in which 

 the silkworm wraps itself. They, indeed, come 

 forth in a variety of colours, their wings bedropped 

 with gold and scarlet, yet are they but the beings of 

 a summer's day ; both their life and beauty quickly 

 vanish, and they leave no remembrance after them ; 

 but the silkworm leaves behind it such beautiful, 

 such beneficial monuments, as at once record both 

 the wisdom of their Creator and his bounty to 

 man." 



The worm, having finished its cocoon, rests awhile 

 from its labour, and at the same time decreases in 

 size and bulk ; it then throws off its last skin, and 

 undergoes its metamorphosis into a chrysalis, which 

 is of a chestnut colour, and smooth. The time 

 during which the insect remains in this state of 

 lethargy is generally from fifteen to thirty days, as 



