STATES OF INSECTS. 297 



from their cases ; but you must be puzzled to conjecture 

 how the wings, which seem as thin, as much expanded, 

 and as rigid as those of a fly, can admit of having any 

 sheath stripped from them ; much less how they can be 

 withdrawn, as they are, through a small opening at the 

 base of the sheath. The fact seems to be, that though 

 the outer covering is rigid, the wing inclosed in it, not- 

 withstanding it is sometimes more than twenty-four hours 

 before the change ensues, is kept moist and pliable. In 

 proportion, therefore, as the insect disengages itself from 

 the anterior part of the skin, the interior or real wings 

 become contracted by a number of plaits into a form 

 nearly cylindrical, which readily admits of their being- 

 pulled through the opening lately mentioned; and as 

 soon as the insect is released from its envelope, the plaits 

 unfold, and the wing returns to its former shape and di- 

 mensions. Thus our little animal, having bid adieu to 

 its shirt and drawers, becomes, but in a very harmless 

 sense, a genuine descamisado and sansculotte. It does 

 not seem improbable, that the pellicle we have been 

 speaking of is analogous to that which, in addition to the 

 outer skin, incloses the limbs of Lepidoptera, &c. in the 

 pupa state, but which they cast at the same time with the 

 puparium, and leave adhering to it a . 



The body of newly-disclosed insects commonly ap- 

 pears at first of its full size ; but the aphidivorous flies 

 (Syrphus F. &c), and some others, in about a quarter of 

 an hour after leaving the pupa become at least twice as 

 large as they were at their first appearance : this appa- 

 rent sudden growth, which is also noticed by Goedart, 



a Reaum. vi. 505 — . t. xlvi./. 9. Comp. De Geer ii. 627 — . 



