hold of the upper part of it with your left hand. Now clench your
right fist and bring it toward your shoulder. Can you feel the elastic
pads, or bands, moving? What are they doing? They are pulling your
hand up to your shoulder. When you walk, you can feel the elastic
bands moving your legs along. So every move we make, these elastic
ropes are at work pulling us about and letting us sit down and making
us run and jump. We call them _muscles_.

You have perhaps seen jointed dolls. The strings and rubber bands on
their joints help to make them move; but the dolls don't act as if
they were alive. They have no telephone system to tell their bodies
how to move.

If you will stop and think how many "moves" you make in a day, you'll
know how hard your muscles have to work. They'd be quite tired out if
they did not have plenty to feed on all the time and did not rest at
least nine hours a day. I told you how the food is melted and carried
about in the blood. It is the blood that brings the muscles their food
and keeps them alive and makes them strong enough to move the joints
and the bones.

What does all this playing do for you? It makes you grow not only big,
but strong, too. What puny little things you'd be if you couldn't get
out and run and play and make your muscles strong and your nerves do
just what you tell them to do.

I know of ten or twelve little chickens that hatched a few weeks ago.
There are so many cats about, that the poor little chicks have to be
shut up in the barn all day. At first they ran and played and jumped
on their mother's back, but now they hump their shoulders and hang