TO-DAY we will use our net. Hold the stick tight, and
throw the net out into the pond as a fisherman throws a
fly. Then the stone will sink the net slowly. If now
you pull it gently through the mud and water-plants,
you are sure to get something.
Bring the net to land and lower it on the grass, and
put all you can find into the clear water in the
bottle. You may find a little fish, or some tadpoles,
or water-snails. Or there may be one of the curious
creatures shown at a, on page 10. I'm sure you would
not think this was the grub of a dragon-fly. But it is.
It is a long insect, all joints, with six legs, and
eyes something like those of the dragon-fly. It has no
wings, but a curious kind of arm, with pincers at the
end, comes out from under its chin.
This is really part of its under-lip. It is called a
mask, and has a hinge, so that it can be folded back
under the chin. Now when the grub wants food, he waits
quietly in the mud, till a beetle or a water-bug passes
by. Then he throws out his mask, and catches his prey
with the pincers.
Look next at the end of its tail. Sometimes it is
pointed, sometimes it opens out like the leaves of a
flower. When it is open the grub
 draws water in, and uses the air in it to breathe.
Then it shoots the water out and so pushes itself
across the pond.
This dragon-fly grub lives at the bottom of the pond
for two years. So you ought to catch one sometime if
you try. It changes its skin many times, and grows some
wing-stumps. Then it creeps up a stem, as we saw in the
last lesson, and becomes a dragon-fly.
And now what is this is our net? At first you may think
it is only a bit of stick, or a piece of mud with
little stones in it, or a number of bits of grass
matted together. And so it is. But there is something
alive inside. If you look carefully you can see the
head of an insect sticking out with six legs behind it.
 is a soft little creature called a caddis-worm. If
you clear off the pieces of grass, or stick, or small
stones, or shells, you will find the soft grub inside.
It has six legs and a number of little tufts under its
body. It breathes with these tufts just as the tadpole
does with its tufts.
You may often see caddis-worms creeping along the
bottom of brooks, looking like tiny moving bundles of
sticks or stones. You may pick them up without using a
net. They build these cases round themselves to try to
protect their soft bodies, which the fish like to eat.
By-and-by they will turn into little yellow-brown flies
like moths. They rise and fall in the air over the
water in the evening. We did not see them with the
May-flies and gnats, because they do not like the
You will very likely fish out a good many little water
grubs in your net. But you must look carefully, for
they are very small. Some have tufts all along their
sides. These are the grubs of the gnats and May-flies
you saw flying over the pond. They all live some time
in the water. And when they come out into the air they
do not live more than a few hours.
CADDIS-GRUBS AND CADDIS-FLY