ey
sometimes seem to need none at all, and they take no food.

May wants to know what these queer water boatmen eat.

They suck out the juices of other insects.

They must lay their eggs in the water, little Nell thinks.

And so they do, on water plants.

Near the city of Mexico there are species that lay enormous quantities
of eggs in the ponds, and what do you think? The Indians mix these eggs
with meal, make them into cakes, and eat them.

The Mexican bugs are gathered by the ton, too, and sent to England as
food for cage birds, fish, and poultry.

Little Nell thinks there must be a great many bugs in a ton. Indeed,
there are, probably about twenty-five millions of them; so you can
imagine Mexico is well supplied with water boatmen!

When the young ones hatch out they look like their parents, only, of
course, they are tiny little dots of things that have no wings.

But they eat and grow and moult like other larvae until they are
full-grown insects.

What have you discovered, Ned? You look surprised.

The water boatman has no antennae!

It doesn't seem to have any. But look carefully and I think you will
find some tiny ones tucked away under its head.

Nell wants to know if the water boatman has a thorax and an abdomen.

Indeed, it has, but you will have to look carefully to see them. Its
abdomen is short and thick and hard. The water boatman is much more
compact in form than the Orthoptera, or any of the other insects we have
studied.

You are right, John, an insect with a long abdomen, like the
grasshopper, could not get on very well in the water.

Now, May, take the cover off the tumbler. There!

Our water boatman was not slow to make use of his wings.

Well, good-by and good luck to you, little water boatman.

[Illustration]

THE FUNNY BACK-SWIMMERS

What, John? You know a water boatman that swims on its back?

That makes Nell laugh, and no wonder.

Yes, there is a little bug that swims on its back.

[Illustration]

It is very much like the water boatman, and it has long paddles made of
its queer hind legs.

Unlike the water boatman, however, its back is not flat but is shaped
like the keel of a boat.

This being the case, it just turns over and swims with its keel-shaped
back in the water.

It is sometimes called the back-swimmer, and most boys are well
acquainted with it.

What do you think about catching it in your fingers, Ned?

Ah, you do not like to!

It has