ESCAPE OF THE COSSUS. 277 



might thrust himself forwards as he lay on the 

 ground, by pushing against any object with his 

 feet. In this way the patient creature moves, we 

 may be sure, by very slow degrees ; but that matters 

 little ; it moves until it has at length reached the 

 opening of its gallery outside the tree, where it 

 may often be seen sticking out half way. Here, 

 by a remarkable instinct, it ceases to move for- 

 wards, for it would otherwise tumble down, and 

 probably destroy itself. At length, after violent 

 struggles, its swathing bands are all either torn 

 asunder, or slidden off, and the insect wings its 

 way in unrestrained freedom far from the scene of 

 its triumphs of patience and hope. The pupa of 

 the " father long-legs" makes its way up from the 

 subterranean chamber in which it has so long been 

 sheltered, fed, and protected, and reaches at length 

 the surface of the ground, where it becomes the 

 perfect insect. 



But other pupae, although not, perhaps, quite so 

 arduously placed as in the last instance, neverthe- 

 less present us with an extremely difficult puzzle, 

 as to how the included insect is to be extricated 

 from its swathing bands. The common flesh-fly, 

 or blow-fly, for instance, in the pupa state is shut 



