64^ STATES OF INSECTS. 



When excluded from the body of the mother, or from 

 the eag, as has been before observed, some insects appear 

 nearly in the form of their parents, which, with a very 

 slight alteration, they always retain; others, and the 

 greater number, assume an appearance totally different 

 from that of their parents, which they acquire only after 

 passing through various changes. It is to these last, which 

 have chiefly engaged the attention of Entomologists, 

 that the title of metamorphoses has been often restricted. 

 As, however, those insects which undergo the slightest 

 change of form, as spiders do, undergo some change, and 

 almost all insects cast their skins several times a before 

 they attain maturity, Linne and most Entomologists, till 

 very recently, have regarded the whole class as under- 

 going metamorphoses, and as passing through four dif- 

 ferent states, viz. the Egg — the Larva — the Pupa — and 

 the Imago. 



It is obvious, however, that in ovo-viviparous species 

 three states of their existence only come under our cog- 

 nizance, as these, being hatched in the body of the 

 mother, come forth first under the form of larvae. There 

 is even one tribe of insects which presents the strange 

 anomaly of being born in the pupa state. This is the 

 Linnean genus Hippobosca (Pupipara fain. Latr.), to 

 which our forest-fly belongs, the females of which lay 

 bodies so much resembling eggs, that they were long 

 considered as such until their true nature was ascertained 

 by Reaumur (most of whose observations were confirmed 

 by De Geer), who, from their size, which nearly equals 



time oviparous, and at another ovo-viviparous. N. Diet. d'Hist. 

 Nat. xii. 568. 



a I say almost all insects, because the larvae of Hymenoptera and 

 Dipt cm are supposed not to undergo this change. N. Diet. a" Hist. 

 Nat. xx. 365. 



