On bare granite boulders in the fields, on the rocky ruins at the foot of mountains, and even on the mountain tops themselves, on projecting rocks far above the snow line, you find the lichens. On rock of every kind they settle down and get to work. They never complain of the climate--hot or cold, moist or dry. When the land goes dry they simply knock off, and then when a little moisture is to be had they're busy again. A little goes a long way with members of the family who live in regions where water is scarce. Indeed, most of them get along with hardly any moisture at all. The very hardiest of them are so small that a whole colony looks like a mere stain upon the rock. While lichens are generally gray--they seem to have been _born_ old, these queer little men of the rock--you can find some that are black, others bright yellow or cream-colored. Others are pure white or of various rusty and leaden shades. Some are of the color of little mice. To make out any shapes in these tiny forms, you must look very close; and if you have a hand lens you will be surprised to find that this fairy-land of the lichens isn't so drab as it seems to the naked eye. For there are flower gardens--the tiny spore cups. Some of them are vivid crimson and, standing out on a background of pure white, they're very lovely. Some of the science people believe the colors attract the minute insects that the lens shows wandering around in these fairy flower gardens. But just what the insects can be there for nobody knows, since the lichens are scattered, not by insects, but by the wind. As a rule lichens grow only in open, exposed places, although some are like the violets--they enjoy the shade. Some varieties grow on trees, some on the ground, others on the bleached bones of animals in fields and wastes and on the bones of whales cast up by the sea. Of course the whole country was awfully wild when the continents first came out of the sea, but that just suited Mr. Lichen, for there is one thing he can't stand, and that is city life, with its smoke and bad air. "Why, one can't get one's breath!" he says. WHY THE LICHENS DISLIKE CITY LIFE So, while you will not meet Mr. Lichen in cities--at least, until after the people are all gone; that is to say, on ruins of cities of the past--you will find him beautifying the ancient walls of abbeys, old seats of learning like Oxford, and the tombstones of the cities of the dead. Mr. Lichen always travels light. On the surface of the lichens are what seem to be little grains of dust, and these serve the purpose of seeds. A puff of wind will carry away thousands of them, and so start new colonies in lands remote.