Helen: The head, trunk, and limbs.

Mother: You said the tree was covered with bark. Look at your hand. With what is it covered?

Amy: With skin.

Mother: Yes; we will talk more about this soft covering of the body at another time. We found these body-houses of ours are made to walk, work, run, jump, and do many other things. How are our limbs different from those of a tree?

Percy: They have joints so they can move many ways.

Mother: You may all put your arms out straight. Now raise them above your head and then touch your head without bending them.

Helen: We can’t do it, mother.

Mother: Let us see, then, how many joints, or bending-places, we have. We will call them the hinges of our house, for they help us to use our limbs, just as the hinges of a door help us to open or close the door. Please bend your arm and tell me how many parts it has.

Percy: My arm has two parts.

Mother: What do you think would be a good name for the part near your shoulder?