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the spinning apparatus (fillers). The number 

 of feet varies from twelve to sixteen, six of which 

 are placed beneath the first three segments of the 

 body, and are preserved by the perfect insect 

 after a change of form. By means of the thread 

 which they spin, they are enabled to descend 

 from one branch to another, or to reascend, 

 by seizing the silken cord between their teeth, 

 and curving up that portion of the body in which 

 the six true legs are situated. The insect then 

 lays hold of the cord with the last pair, which 

 secures it another fixed point, it then lifts up 

 its head a second time, lays hold of an addi- 

 tional portion of the thread, and, by a repetition 

 of its former action, it gradually ascends to the 

 point which it wishes to reach, and, when safely 

 landed, it disembarrasses itself of the silk which 

 has been collected. These caterpillars are fur- 

 ther enabled by the same thread to escape their 

 enemies ; and they never move without taking 

 the precaution of having a thread ready to sus- 

 tain them in the air, if they should happen to 

 fall. 



During their life time they change their skin 

 three or four times ; and, when they have attain- 

 ed their full growth, they spin a cocoon, in which 

 they enclose themselves to undergo their meta- 

 morphosis. In the construction of this cocoon, 

 the silk-worm uses silk only, but caterpillars in- 

 troduce other extraneous bodies, particularly 

 hairs. 



I stated, that after a certain period, the cater- 



