INSECT SUCKERS AND BITERS. 221 
obtained their wings they lived for nearly two years 
at the bottom of the pond over which they now fly. 
Their real life is that of a water-insect (mg) 9 which 
as soon as the eggs are hatched, dives to the bottom 
of the pond and burrows in the ground or under 
stones, and feeds upon all passing insects, seizing 
them with strong spiny jaws, and devouring them 
greedily. At this time the May grub does not 
breathe through holes in the side, but has its body 
fringed with gills or delicate folds of skin which take 
in air out of the water, and there is nothing in its 
appearance to lead any one to believe that it could 
ever live in the air. But as it grows up and loses one 
loose skin after another, the rudiments of wings are 
seen through the transparent covering, and then the 
end of its life is beginning. It creeps out upon some 
plant or stone overhanging the water, the skin cracks 
down the back, and the flying insect comes out with 
its wings perfectly visible. Still it cannot use them, 
for a fine film covers the whole body, and it is only 
a few hours after, when this has dried and split, that 
the perfect May-fly soars away an air-breathing insect, 
to lay its eggs and die. 
We need not then pity these frail, delicate eph- 
emera on account of their short life, for they have 
had a long and merry one feeding in the pond below, 
and when we see them, they are taking their last 
enjoyment before night falls. 
The same thing is true of the caddis-flies or water- 
moths {cf y Fig. 75), which anglers use as bait, for 
they too cannot feed after they get their wings ; but 
their life in the pool below has been rather different. 
Their tail is soft like that of the hermit-crab, and they 
