INSECT TRANSFORMATIONS 1463 



tus can be folded upon the head, when it gives to the 

 larva the appearance of being masked, and hence the 

 name of "mask" which has been applied to this struc- 

 ture. But on the approach of some unwary insect, 

 the jaws can be rapidly extended to seize the unfor- 

 tunate victim, and convey it to the mouth of its cap- 

 tor. The dragon-fly's young are thus purely aquatic 

 in habits, and propel themselves along by ejecting 

 water, which has been used in breathing, from the 

 posterior extremity of the body. 



Having arrived at the close of its chrysalis-stage 

 of development the chrysalis differing from the 

 larva simply in its greater size, and in the develop- 

 ment of the wings and perfect body within the pupa- 

 skin the insect at length fixes its body to some water- 

 plant. The pupa-skin next splits along the back, and 

 the mature, winged insect slowly emerges therefrom. 

 The crumpled wings soon dry, and acquire their nor- 

 mal consistence; and the dragon-fly, freed from the 

 trammels of a mundane existence, mounts into the 

 air, and "revels in the freedom of luxury and light." 

 Tennyson has aptly described this change in his lines : 



To-day I saw the dragon-fly 



Come from the wells where he did lie. 



An inner impulse rent the veil 

 Of his old husk : from head to tail 

 Came out clear plates of sapphire mail. 



He dried his wings : like gauze they grew : 

 Thro' crofts and pastures wet with dew 

 A living flash of light he flew. 



In these latter instances, as in the case of the but- 

 terfly, the nutrition of the insects has been proceeding 



