Houghton Mifflin Company for the pictures from Sharp's "Year Out of Doors" on page 11; "Riverside Natural History" on page 117; Mill's "In the Beaver World" on pages 152 and 153.
Ginn and Company for the pictures from Breasted's "Ancient Times" on page 67; "Agriculture for Beginners" on page 47; Bergen's "Foundation of Botany" on pages 49, 190, and 197; Bergen's "Elements of Botany" on pages 193 and 195; Beal's "Seed Dispersal" on page 51.
U. S. Geological Survey for the pictures on pages 21, 22, 23, 30, 31, and 59.
New York Zoological Society for the pictures on pages 145, 159, and 216.
_School Arts Magazine_ for the picture on page 221.
U. S. Department of Agriculture for the pictures on pages 125 and 189.
American Museum of Natural History for the pictures on pages 20, 24, 26, 139, and 162.
Cassell and Company for the pictures from "Popular History of Animals" on pages 118, 177, 179, and 217; "Popular Science" on page 242.
Hutchinson for the pictures from "Marvels of the Universe" on pages 92, 101, 103, 141, 169, and 173; "Marvels of Insect Life" on page 211.
The Dunham Company for the picture on page 45.
International Harvester Company for the picture on page 199.
Northern Pacific Railway for the pictures on pages 235 and 237.
It will be understood, as stated in the preface, that, like "The Strange Adventures of a Pebble," this is an autobiography. In other words, it is the grain of dust itself that tells the story of the life of the soil of which it is a part.
In truth you'll find it hard to say How it could ever have been young It looks so old and grey.
Some say it was Leif Ericson, some say it was Columbus, but _I_ say it was The Little Old Man of the Rock.
And I go further. I say he not only discovered America but Europe, Asia, and Africa, and the islands of the sea. I'll tell you why.
I. HOW LITTLE MR. LICHEN DISCOVERED THE WORLD
As everybody knows, we must all eat to live, and how could either Columbus or anybody else--except Mr. Lichen--have done much discovering in a world where there was nothing to eat? When the continents first rose out of the sea[2] there wasn't anything to eat but rock. Rock, to be sure, makes very good eating if you have the stomach for it, as Mr. Lichen has. It contains sulphur, phosphorus, silica, potash, soda, iron, and other things that plants are fond of, but ordinary plants can't get these things out of the rock--let alone human beings and other animals; and that's why Mr. Lichen had the first seat at the table and always does.