NATURAL HISTORY. 159 



" The first is the same which you saw in 

 the last picture, only in this drawing the head 

 is uppermost. But its last change, when it 

 becomes an insect with wings, is the most 

 curious part of the whole. When it is about 

 to get its wings, and become a perfect gnat, it 

 raises its shoulders just above the top of the 

 water, and its skin cracks, so that the head of 

 the gnat immediately comes through. The 

 shoulders come next, and make the crack 

 larger ; but it has yet all its body to get out, 

 and its legs and wings are as yet all shut up 

 in its case. Now is the time of danger for 

 the gnat. It raises itself nearly straight out 

 of the crack, and by wriggling works its body 

 along : and if a particle of water should get 

 upon the case, or touch its wings, it would be 

 overset, and must perish. Thousands and 

 thousands die in this way. It is so very 



