34 PARTIAL ORISMOLOGY. 



The names he proposed for the, according to him, several kinds of 

 metamorphoses are the following : 



COMPLETE (m. completa) is, according to him, that species of 

 change wherein the larva is formed exactly like the perfect insect. 

 It is found only among such as are destitute of wings in their perfect 

 state (e. g. Pediculus, Cimex). 



SEMI-COMPLETE (m. semi-completa), when the young resembles the 

 parent with respect to form, but is as yet deficient in the wings peculiar 

 to the latter. 



INCOMPLETE (in. incompleta), when the young creeps from the egg 

 as a maggot, and the pupa has free, distinct limbs, although quiescent 

 (Hymenoptera, Coleoptera). 



OBTECTED (in. obtecia], is the change only distinguished from the 

 latter by the limbs, as well as the body, being enclosed in a hard 

 corneous case, upon which their form and position are strongly indicated 

 (Lepidoplera}. 



COARCTATE (m. coarctato} he calls, lastly, that change wherein the 

 larva is a maggot without legs, and the pupa is enclosed within a round, 

 almost egg-shaped, corneous case, upon which there is not the least 

 indication of the parts of the perfect insect. 



In opposition to this apparently very precise distinction of the 

 different kinds of metamorphoses, we may object that many cases occur 

 which will not admit of being arranged under any of those heads ; for 

 example, the larva of Xylophagus is without feet, and yet the limbs of 

 the perfect insect are perceptible upon the pupa case ; it is the same 

 with the genus Stratiomys ; and again, a footless maggot is trans- 

 formed into a pupa with free limbs, as in Ichneumon. Exclusive of 

 these considerations the idea of a complete change is most strictly appli- 

 cable to what Fabricius terms incomplete, and his most complete, on 

 the contrary, being evidently the most incomplete. It consequently 

 appears to us preferable to adopt but two chief kinds of metamorphoses, 

 as, as we have seen, between the several subdivisions, very many 

 connective and alternative conditions exist. 



52. 



The larvae of insects with an imperfect metamorphosis, are to be 

 recognised in general by their want of wings and scutellum ( 76) 

 with the exception of the few instances wherein the perfect insect has 

 no wings. In such cases certainty can be derived only from their relative 

 size in knomv species, as the larvae are invariably smaller than the 



