When we realize that this muddy color always means that the water is filled with soil, all that it will hold in solution, that it is carrying away the top soil, which is best for agriculture, and, finally, that every little streamlet and creek, as well as the mightiest river, is carrying this rich soil-deposit downward toward the sea in its flow, we begin to see how great a factor erosion is in the wasting of the land. The Missouri River, which drains a large area of wheat and corn land, is notable as a muddy, yellow river at almost all seasons. Do you understand what that means? It means that this great productive region is growing poorer each year, and that as the population increases, and the need of great harvests increases, the land is becoming less able to produce them. The Mississippi River is said to tear down from its banks more soil each year than is to be dredged from the Panama Canal. At the mouth of the river is a delta many miles in extent, formed wholly of land that has been carried down the river. The soil in lower Mississippi and Louisiana is almost black, and is in many places seventy feet in depth, and it has all been left there by the river, which took it from the higher lands. It is estimated that our rivers carry out to sea one billion tons of our richest soil each year. The ancient Egyptians worshiped the Nile because each year the spring floods left behind the rich soil deposits that fertilized their fields and gave them an abundant harvest. Entire fields and even whole farms along the upper stretches of the Mississippi and Missouri have been carried away, not the top soil only, but the land itself, by the swift current of the springtime floods as they cut a new channel for the river. Canaan, the "land of promise" of the Bible, was once an abundant region, "flowing with milk and honey" in the language of Moses, with its grapes, its vast forests of cedar, fir, and oak, its treasures of wheat, olive-oil, and other rich agricultural products. Now all are gone. The entire country seen by the traveler in the Holy Land to-day is one of the most desolate regions on the globe, where the few inhabitants are scarcely able to obtain a scanty living.