PHENOMENA OF THE CHANGE. 305 



duced by a contrivance similar to that mentioned in 

 the case of the blow-fly, a sort of air bladder which 

 the insect distends at its pleasure, and thus causes 

 the skin covering its head and eyes to split open. 

 The head and body of the insect rise and make 

 their appearance through the slit ; and the head is 

 now so much larger than it appeared while in the 

 pupa case, that it seems almost impossible that it 

 could ever have been contained within it. The 

 insect continues to rise perpendicularly out of the 

 case, and the legs make their exit, leaving the leg 

 cases of the pupa undisturbed in their attachment 

 to the support on which it rests. In order to 

 facilitate the disengagement of the rest of its body 

 the insect now bends itself in a curved form 

 backwards, being only kept from falling by the 

 last rings or segments of its body being still 

 embraced by the sheath of the pupa case. When 

 it has extricated itself thus far, it begins to move 

 about its legs in different directions for several 

 minutes, as if to get them into use ; but after this 

 it ceases all movement whatever. Not a quiver 

 can be seen in its limbs, and the young observer 

 would be inclined to conclude, as a great entomo- 

 logist once did, the first time he witnessed the 

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