Lynn Blackwood, age l2, of Mocksville, NC for her question:
What causes fungus?
A fungus infection seems to spread through a class or family in a most mysterious manner. A moldy fungus seems to arrive from nowhere to attack a loaf of bread. A mushroom ring pops up overnight from who knows where. Yet these and other strange fungus appearances can be traced and explained.
All life springs from life, and every living thing came from parents or other living things like itself. This is a law of nature, and the fungus plants, which are living things, must obey it. Mycologists who study them know of some 75,000 different fungi. They have no stems or leaves or flowers, and not one of them is green. Nevertheless, the assorted fungi are plants, and as plants they are living things.
The biggest of them is the giant puffball, 2 feet wide and often shaped like a bulgy beach ball. The best known fungi are mushrooms and toadstools, but many of the 75,000 are midgets, too small to be seen as individuals without the help of a microscope. All fungi, large and small, can multiply by producing seed like spores. Yeast and certain other fungi also may multiply by budding new offspring somewhat like plant shoots.
If you kick a giant puffball at the right time, a cloud of dust will puff out into the air. The dusty specks may be 7 million million spores launched on the breezes. Maybe a half dozen of them will be lucky enough to land on a suitable spot where they will start or cause a new puffball.
Many fungi are no bigger than the spores of the puffball. Imagine, then, how small their spores must be. These midget plants are plentiful everywhere, and swarms of their invisible spores are in the soil, in the air and on most of the things we touch.
A stray fungus spore may drift into the kitchen through the finest screen and perhaps land on a slice of bread. It thrives and grows and soon causes a patch of mold big enough to be seen. Some fungi attack human skin. Your touch may transfer these invaders and cause healthy skin to become fungus infected.
Most of the fungus plants do not directly affect us. The mushrooms and truffles are delicious food items, but many toadstools are deadly poisonous. A few fungi cause diseases in plants or animals. We must share our world with this teeming assortment of midgets, so we must learn how the dangerous ones cause trouble and how to protect ourselves from them.