272 CLASS vni. 



Most Insects quit the egg in a form entirely different from that 

 which they afterwards possess. An impregnated female butterfly, 

 for instance, deposits eggs, from which caterpillars proceed, which 

 present not the slightest external resemblance with the mother. 

 They are vermiform creeping animals, provided with different pairs 

 of feet, which eat enormously, grow rapidly, cast their skin often, 

 and at the last casting change into quite another creature, with a 

 very hard and horny skin, which has no limbs, does not move from 

 its place 1 , takes no food, and falls as into a death-sleep. There 

 may however be generally discerned in the seemingly formless 

 mass, on close observation, the external parts of the butterfly, 

 which folded and rolled together are concealed beneath the horny 

 shell, on whose surface they are traced out. After a longer or 

 shorter time, sometimes only after many months, the perfect insect, 

 the butterfly, quits its narrow cell. At first the wings are short, 

 moist and unfit for flying, but soon unfold themselves, become dry, 

 and then support the flapping Insect through the air, which soon 

 fulfils its new destiny, the propagation of its kind, and dies 2 . 



In these changes of form (metamorphoses] of Insects the first 

 form or first state is called that of the maslc or larva, and the 

 Insects are then named caterpillars, maggots, &c. The second state 

 is that of nymph or pupa (in day-butterflies called also chrysalis}. 

 The third state is that of the perfect insect (insectum dedaratum, 

 imago) . 



All Insects do not pass through this threefold state. The wing- 

 less hexapod Insects,, with few exceptions, leave the egg in the 

 same form which they afterwards retain ; only the rings and the 

 feet become more numerous in the Myriapoda. These Insects 

 LATREILLE names Insects without metamorphosis. No winged 

 Insect, on the other hand, comes from the egg with wings ; but 



evolutione (De generatlone Insectorum in ovo), Francof. ad Mcen. folio, Fasciculi u. (not 

 completed), relate principally to Musca vomitoria and some Lepidoptera, but do not 

 give so much information as might have been expected from the diligent and patient 

 investigations of the author. 



1 If the pupa be however in such a situation that the perfect insect would not be 

 able to come out of it (in the branch of a tree, for instance), then it changes its place 

 towards the period of the last change, by pushing on its body by contraction, a motion 

 assisted in many cases by little hooks on the rings of the abdomen. 



3 Sometimes the perfect insect, shortly after its coming forth, once more changes 

 its coat, as is commonly known of the Ephemera. 



