8 INSECT ARTIZANS AND THEIR WORK 



The average length of silk wound off from a single 

 cocoon is 1,526 feet; but there is a difference 

 between the produce from a cocoon containing 

 female chrysalis and one containing a male sufficient 

 to enable the silk-farmers to sort out the sexes by 

 the weight of the cocoons. In agreement with thi 

 result it is found that a Silkworm that is to develo] 

 into a female moth has larger silk-glands than one 

 that is to become a male moth. 



The history of the domestication of the Silk 

 worm, like that of the Honey-bee, extends so fa 

 back that its beginnings are hidden in the mist 

 of antiquity. Silk is known to have been in genera 

 use among the Chinese at a period compared wit] 

 which the introduction of the insect to Europ 

 may be spoken of as recent. Silk tissue reachec 

 Europe from Asia long before anything certaii 

 was known here as to its origin, " some supposing 

 it to be the entrails of a spider-like insect wit 

 eight legs, which was fed for four years upon a 

 kind of paste, and then with the leaves of the green 

 willow, until it burst with fat ; others that it was 

 the produce of a worm which built clay nests and 

 collected wax ; Aristotle, with more truth, that 

 it was unwound from the pupa of a large horned 

 caterpillar. 



" Nor was the mode of producing and manu- 

 facturing this precious material known to Europe 

 until long after the Christian era, being first 

 learnt about the year 550, by two monks, who 

 procured in India the eggs of the Silkworm moth, 



