EXPANSION OF PERFECT INSECTS. 



337 



A, the dragon-fly, beginning to escape from the pupa; a, the fly; 6,the 

 pupa case. B, The process further advanced; c, the fly; d, the pupa 

 case. C, the fly nearly free, and forming an arch; e, the fly;/, the 

 pupa case. D, the fly bending back its body, so as not to obstruct the 

 expansion of the wings. 



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