196 PTILOTA. 



a decidedly incorrect mode of proceeding ; since by this means 

 the metamorphosis of an insect is said to be perfect when the 

 pupa state is perfect (that is, active, and resembhng the per- 

 fect insect, except in wanting wings) ; whereas it must be evi- 

 dent that this kind of metamorphosis must, as compared with 

 other species, be the least perfect and complete ; and, on the 

 other hand, the imperfect metamorphosis, or that having 

 the most imperfect pupa, must for the same reason be the 

 most complete and perfect change which any of these insects 

 undergo. 



Linnaeus first applied these and similar terms, and most 

 appropriately, to designate the variations, not of the nature 

 of the metamorphosis, but of the pupa. They were as fol- 

 low : — 



1 . Pupa completa, active, with all the parts of the perfect 



insect. Example, Aranea, Acarus, Oniscus. 



2. Pupa semicompleta, active, resembling the parent, but 



having only rudiments of wings. Example, Gryllus, 

 Cicada, Cimex, Libellula, Ephemera. 



3. Pupa incompleta, inactive, but with rudimental wings 



and legs. Example, Apis, Formica, Tipula. 



4. Pupa obtecta, \^ath the thorax and abdomen distinct, 



inclosed in a scaly covering, i. e., corticata, and either 

 naked or inclosed in a cocoon. Example, Lepido- 

 ptera. 



5. Pupa coarctata, inclosed mthin a globular or oval case, 



formed of the skin of the larva. Example, 'Musca, 

 (Estrus. 



Now the true winged insects necessarily suffer only the 

 fom* latter species of metamorphosis ; although in those spe- 

 cies of the semicomplete kind, which have no wings in the 

 perfect state, it may with equal propriety be said that they 

 belong to the first section, in which the pupa is complete : 



