Nell says it is not like silver any more, but just a little black and gray speckled bug.
That is because it is now on top of the water. When it goes under it is surrounded with a layer of air, and that is what makes it look as though it had on a silver dress.
May wants to know how it manages to take a layer of air down under the water. If you were to look at it with a magnifying glass, May, you would see it is covered with fine hairs; the air becomes entangled in these hairs. Do you not remember how the leaf of the jewel weed, or touch-me-not, as it is also called, shines when you plunge it in water? It, too, is covered with fine hairs that hold air. Many leaves shine in this way when put under water, and always because of the fine hairs that prevent the air from being pushed out by the water. You see the hairs on the bugs serve the same purpose as those on the leaves; they hold fast the air.
Our water boatman breathes this air that surrounds him.
You know how insects breathe do you not?
Dear me, then I shall have to tell you.
They have no lungs; of course, so they cannot breathe with lungs as we do.
Take a long breath—see how your chest rises—that is because you filled your lungs full of air.
Well, the insects have to breathe air.
Every living thing has to breathe air. Nothing in the world could live without air.