136 INSECTS. 



dim in hue an almost mud-coloured insect, with large 

 lustreless wings and three shortish tails, may some- 

 times be seen standing on the wall of a chamber, or in 

 some other situation more or less remote from the water 

 whence it has emerged, and to which it must have flown. 

 In a little while a beautiful insect, with clear and deli- 

 cately veined wings, is seen standing by the side of 

 something which might be taken for its ghost, so dim 

 and unsubstantial a likeness is it, as with shrivelled and 

 shapeless wings, it stands there in precisely the same 

 attitude, its long tails extended and legs grasping the 

 wall. This ghost is a most delicate skin, which en- 

 veloped the whole insect, wings, limbs, and all, and en- 

 closed in which the fly had left the pupa-case. 



In this way the Ephemeron appears to undergo an 

 extra metamorphosis, but the fact of a delicate membrane 

 covering the insect within the pupa-case is common in 

 other orders, and some insects emerge with more or less 

 of this attached to them. The long-horned bee is a 

 common example of this, as it is usual to find the 

 newly-emerged males with a delicate skin remaining on 

 their antennae, and which is afterwards stroked off by 

 their spurred legs. 



When arrived at perfection the male Ephemera, whose 

 life, as their name denotes (f0r////>oe, ephemeras; 

 diurnal) does not, in some species, extend beyond 

 the day indeed, seldom beyond a few hours spends 

 nearly the whole of this brief space upon the wing.* 



The mouth is so imperfectly developed that there is 



* The brevity of the life of these insects was not unobserved by the 

 Ancients ; and if the antique gem of which an engraving is placed at the 

 head of the chapter on Lepidoptera (described p. 11), is truly figured, 

 it would seem that the Ephemera, not the Butterfly, is here represented ; 



