I METAMORPHOSES .OF INSECTS 13 



its covering, and the insect emerges perfect in all its 

 parts. Sometimes a little while elapses ere it takes 

 to flight. The wings of butterflies and moths are 

 somewhat drooping and difficult to spread, and the 

 body is humid and soft. After considerable res- 

 piratory effort, and a rest, and exposure to the 

 drying influence of the atmosphere, the imago gains 

 strength and solidity, its wings enlarge and expand, 

 and at last it enters on its higher career and the 

 delight of finished faculties. Humble bees do not at 

 once come abroad to the outer air in their new dress. 

 Their bodies are excessively moist and weak when 

 they emerge from the cells, and their hairs are of 

 a whitish gray. They crowd together in the nest, 

 and seem to feel the chill of diminished warmth. In 

 a few hours the susceptibility vanishes, and the 

 proper colours are acquired, but the bees are not 

 vigorous or capable of great exertion until the 

 following day. 



When an insect has withdrawn from the pupal case 

 it is perfect in form, its internal organs are perfect, and 

 metamorphoses are now concluded. An apparent 

 exception to the rule occurs in the case of the May- 

 flies (Ephemerae).* The pupae creep out of the 

 water, and perform the feat of getting rid of the 

 pupal covering, their wings expand, and they take 

 feebly to flight. Shortly however they settle again, 

 and having shed an extremely delicate skin, re- 

 new their aerial excursions with redoubled energy. 

 The condition previous to the final moult has been 

 called the pseudo-imago. 



Metamorphoses being over, the task for the re- 



