290 NATURAL HISTORY. [cH. XVH. 



its vertical position, and allows the skin to drop. If 

 the first series of pirouettes prove unsuccessful, the 

 chrysalis tries another in the contrary direction; 

 and if after repeated efforts it fails to get rid of the 

 nuisance, it calmly and patiently submits to an evil 

 which it cannot remove. 



This vertical position does not however suit all 

 caterpillars ; there are some which fix themselves 

 in an inclined or even horizontal position. To effect 

 this, a set of threads is passed round their bodies, 

 and then attached to the wall or a part of some 

 plant from which they remain suspended. 



These girths or supporting belts are formed in 

 various ways, but always of the same material, — silk 

 spun for that purpose by the caterpillars. The fol- 

 lowing figures Avill explain some of those processes 

 by which the suspension is effected. In the first 



figure (Jig. 1), the caterpillar is seen to bend its 

 body to the point where the end of the thread is to 

 be fixed: in the second (^g. 2), it presents itself 

 in the act of carrying over the body, by doubling it- 

 self on its back : while in the third (Jig. 3), it ap- 

 pears to turn round for the purpose of fixing it on 

 the farther side. When a sufficient number of 

 threads have been thus spun to form its web, the 

 insect gently withdraws its head, assumes a straight 

 position, and quietly awaits the hour of its trans- 

 formation. 



The girth which is passed round the body of the 

 caterpillar in order to suspend it when it shall have 

 aarumed the chrysalid form, is fabricated sometimes 



