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TEXT-BOOK OF ENTOMOLOGY 



And are we to look upon this as our hint that the archaic butterfly 

 in its transformations passed through an active pupal stage, like the 

 lowest insect of to-day, when its limbs were unsheathed, its appetite 

 unabated ? " etc. Scudder also shows that " the expanded base of 

 the sheath covering the tongue affords protection also to the palpi 

 which lie beneath and beside the tongue." 



All this tends to show the importance of studying the structure 

 of the pupa, in order to ascertain how the pupal structures have 

 been brought about, with the final object of discovering whether the 

 pupge of the holometabolic insects are not descended from active 

 nymphs, and if so, the probable course of the line of descent. 



"U.'p 



fc. Mode of escape of the pupa from its cocoon 



" In all protected pupae," as Chapman says, " the problem has to 

 be faced, how is the imago to free itself from the cocoon or other 



envelope protecting the 

 pupa." In the Coleoptera 

 and Hymenoptera the imago 

 becomes perfected within the 

 cocoon or cell, as the case 

 may be, and as Chapman 

 states, "not only throws off 

 the pupal skin within the 

 cocoon, but remains there till 

 its appendages have become 

 fully expanded and com- 

 pletely hardened, and then 

 the mandibles are used to 

 force an outlet of escape," 

 and he calls attention to the 

 fact that "in many cases, 

 even in some entire families, 

 they are of no use whatever 

 to the imago except in this 

 one particular," and he cites 

 the Cynipidae as perhaps the 

 most striking instance of this 

 circumstance. 



In those Neuroptera which 



FIG. 687. Pupa .if m,-rjiii-ri/.r j,ui-j,uritii<t, spin a silken cocoon, 



front view: md, niiiii.lilil.-s: m.r. />. maxillary minus, TT , -, .-, 



end drawn separately ; mx.' p, labial palpi ;///", labrum. -HeinerODlUae, the 



. the 



