So do be careful never to injure the bark of a tree; for wherever it is torn, it leaves an open wound—just as when you scratch your finger or your arm. There are other fungi which you’ve seen oftener than toad stools. They are— MOLDS You’ve often seen the mold which comes on bread which has been left in a rather dark, warm, moist place. The mold comes from the thousands of germs in the dust in air. These germs settle down and use anything possible for food, and send out spore-dust to make more germs. While they are growing and making spore cases, they appear as molds and mildews. The germs in the dust are too tiny to be seen without a microscope, and their near relatives— BACTERIA are about the tiniest of living things. They grow everywhere. Some do us harm and some benefit us wonderfully. Cheese is made out of milk by one of the good kind; another kind makes vinegar; some other kinds fasten themselves to the inside of our mouths and bodies, bringing disease, like typhoid fever and consumption. When we keep our bodies and mouths and teeth clean, we help our blood to destroy such bad bacteria. Sunlight destroys bad germs. Fresh air destroys bad germs. You should have plenty of fresh air both day and night. “Pshaw,” said Jack, as Bet finished speaking; “toad stools are meant for fairies to sit on, and mushrooms for human beings to eat. What kind of nonsense are you trying to teach, anyhow, Bet?” The girls laughed, for they saw Jack wink as he spoke. “Come,” said he, “you’ve been standing too long—come, have a seat on a toad stool?” With that he ran toward a beautiful white mushroom, and Bet followed. When they were seated, Mary Frances asked: “What is the difference between a mushroom and a toad stool?” “Well,” Jack replied, “I guess there isn’t really any difference, although some people think that toad stools, if eaten, poison people and that mushrooms are harmless, but some mushrooms are very poisonous, so do not try to use any you gather, unless some grown people know them to be harmless, for some of the most beautiful would kill you the most quickly.” “I’ve eaten mushrooms,” said Eleanor, “but they were canned ones.” “Oh, they are safe enough,” Bet smiled. Then the fairy clock struck the half-hour. CHAPTER XLVIII SOME WAYS TO RID OF WEEDS “FOUR-THIRTY!” exclaimed Jack, “and we have only until five o’clock.” “My, you’ll have to talk fast,” said Bouncing Bet, “in order to tell all you want to.” “One quarter of all I want to, you mean, Bet,” Jack replied. “I’m afraid my brother and father and mother will come look for us,” said Mary Frances. “No,” Bet shook her head, “not until five o’clock.” “I suppose fairies know,” Eleanor whispered. Jack began to talk rapidly: WEEDS