Billie was visiting his big cousin John. The house where John lived was near a large forest. John had promised to take Willie for a walk in the forest.
''Don't go too far, boys,'' said John's mother.
''We won't,'' smiled John taking Willie's hand.
They went out into a world of green meadows and many green trees beyond.
''We're going to visit a tree factory,'' said John.
''Is that where they make trees?'' asked his little cousin.
''No,'' laughed John. ''The trees themselves are the factories.''
Willie couldn't understand. He lived in a big city where there were many factories. He'd seen them. The factories were tall stone buildings. They had machinery in them. And lots of people to run the machines.
''How can a tree be a factory?'' asked Willie as they walked into the forest.
''I'll show you.'' It sounded a little mysterious.
They walked a ways and stopped before a tall oak tree.
''Now,'' said John, ''tell me what a factory does.''
Willie thought a bit. ''A factory makes things, all kinds of things.''
''So does a tree,'' answered John. ''The tree, first of all, makes a kind of sugar.''
''I don't see it making sugar,'' answered Willie. He was looking for white bags of sugar like the ones in the store.
John smiled. ''It's making a simple kind of sugar inside the tree. The water is pulled up from the soil. And elements are drawn from the air. With the sun shining on this, the tree turns it into sugar. That's how you get maple syrup from maple trees.''
Willie grinned. ''I like it on pancakes. So that's how a tree is a factory - a sugar factory!''
''Yes,'' added John, ''but it's really many other kinds of factory.''
''What else does it make?''
''Let's hide behind this bush and see,'' whispered John.
It was very strange, sitting on the ground and not talking. What was John waiting for? Willie saw John putting his finger to his lips. Then he pointed to the base of the big tree.
A gray squirrel came silently forward. He quickly climbed up the tree. Willie knew his fluffy tail was jerking to keep his balance. The squirrel climbed out onto a branch and pulled off an acorn. Then he put it in his mouth. But he didn't eat it. He carried it in his mouth as he hurried down the tree. Then he disappeared into the woods.
''Where's he going with the acorn?'' whispered Willie.
''He's going to bury it in the ground,'' replied John.
''In the ground? Why?''
''In the winter, squirrels dig up the acorns that were buried earlier. That's when they need food badly.''
''Oh. So the tree manufactures nuts for squirrels to eat.''
''And other animals like chipmunks, and white-footed mice, and bigger animals , too.''
This sounded to Willie like a lot of customers for one tree. ''Won't it run out of acorns?''
John shook his head. ''A big oak tree like this could produce 15,000 acorns in a year.''
''Fifteen thousand! What a factory!''
''More than 80 percent of that is eaten by animals.''
''What happens to the rest, John?''
''Some of it is infested by weevils and moth larvae. There's just a little left, less than 1 percent.''
''What happens to the acorns left over?''
''They fall into the ground and some will grow into big oaks.''
Willie liked this idea. ''So the tree is a tree factory, too!''
''That's right, the tree makes new trees.''
''Does a tree make anything else?''
John put his fingers to his lips again. ''Look!'' he whispered. A white-tailed deer came carefully through the forest. He was so beautiful Willie couldn't keep his eyes off him. The deer stopped at the tree. He stretched his neck so his mouth reached up to the lower leaves. Slowly his jaws moved back and forth as he chewed on a leaf.
''Looks like he's chewing gum,'' giggled Willie.
When the deer had eaten his fill, he moved off.
''Watch now,'' said John. Someone else was coming along. The underbrush moved and a fluffy brown beaver came into sight. He moved very slowly. The beaver had the biggest teeth Willie had ever seen. Funny-looking teeth. He waddled up to the tree and chewed through a low-hanging limb. This he carried off back to the river.
''What's the beaver want with that branch?'' asked Willie.
''Maybe he's going to build something with it. Beavers are nature's architects.''
Then Willie saw a pretty chubby bird.
''A ruffled grouse,'' whispered John. The grouse came along timidly and started to chew at the small saplings growing at the base of the big tree.
When she'd gone away, John said, ''Birds depend on the seeds and buds of the trees.''
Willie could hardly believe all that he'd seen the tree factory provide. He saw John was looking at the red setting sun. ''Time to get back, Willie. Mom will be expecting us on time for dinner.''
Willie had been enjoying himself so much he really didn't want to go. But for hours he'd been watching all the animals eating. And now he was hungry, too.
''I guess we're about the only ones who can't get food from the tree factory, '' he said. John laughed as they walked out of the forest. ''Well, there are always those nuts to eat. And think of all the fruit trees that make food for us.''
''Would you show me how to plant a tree?'' asked Willie when they got to John's home.
''Sure. Where are you going to plant it?''
''In my backyard at home.'' Then Willie burst out laughing. ''I'm going to grow me a factory!''