“It is more wonderful,” said Mr. Blake.  “For the man in the show put the things in my hat by a trick, when you were not looking, and only took them out again to make you think they were there all the while.  But roots, seeds and tomatoes are not exactly inside the seed all the while.  The germ—­the life—­is there, and after it starts to grow the leaves, roots and tomatoes are made from the soil, the air, the water and the sunshine.”

“Are there tomatoes in the air?” asked Mab.

“Well, if it were not for the things in the air, the oxygen, the nitrogen and other gases, about which you are too young to understand now, we could not live grow, and neither could plants.  Plants also have to have water to drink, as we do, and food to eat, only they eat the things found in the dirt, and we can not do that.  At least not until they are changed into fruits, grain or vegetables.”

Hal and Mab never tired looking at the tomato plants growing in the box in the house.  Each day the tiny green leaves became larger and raised themselves higher and higher from the earth.

“Soon they will be large enough to transplant, or set out in the garden,” said Daddy Blake.

Two or three days after their father had told Hal and Mab why seeds grow, the children, coming home from school, saw something strange in their garden.

There was a man, with a team of horses and the brown earth was being torn up by a big shiny thing which the horses were pulling as the man drove them.

“Oh, what’s that in our garden?” cried Hal to Uncle Pennywait.

“It’s a man plowing,” said Hal’s Uncle.

“But won’t he spoil the garden?” Mab wanted to know.

“He’s just starting to make it,” Uncle Pennywait answered.  “Didn’t Daddy Blake tell you that the ground must be plowed or chopped up, and then finely pulverized or smoothed, so the seeds would grow better?”

“Oh, yet, so he did,” Hal said.

“Well, this is the first start of making a garden,” went on Uncle Pennywait.  “The ground must be plowed or spaded.  Spading is all right for a small garden, but when you have a large one, or a farm, you must use a plow.”

Mr. Blake owned a large yard back of his house, and next door, on the other side from where the new Porter family lived, was a large vacant lot.  The children’s father had hired this lot to use as part of his garden.

Hal and Mab watched the man plowing.  He held the two curved handles of the plow, and it was the sharp steel “share” of this that they had seen shining in the sun as it cut through the brown soil.  A plow cuts through the soil as the horses pull it after them, and it is so shaped that the upper part of the earth is turned over, bringing up to the top, where the sun can shine on it, the underneath part.  The undersoil is richer and better for seeds to start growing in than the upper part, where the rain may wash away the plant-food things that are needed to make a good garden.