32 TALKS ABOUT THE SOIL, 



thousands of years, only to be destroyed and over- 

 turned. Earthquakes, sinkings in the seas, showers of 

 dust from volcanoes, floods and fires, swept away all 

 traces of old soils and old forests, till only the rocks 

 remained ; yet in all there was progress, and the last 

 new soil formed of dead plants and the remains of 

 more ancient rocks now covers all the land. Every 

 plant that has ever lived helped in some degree to 

 make a soil for other plants. Every leaf that falls, 

 every plant dying of old age or destroyed by frost or 

 fire, leaves its gift for the plants that are to come after 

 it. We have only to observe the thick carpet of fallen 

 leaves under the trees in the woods, to see that each 

 year the trees add to the soil in which they live. We 

 walk along the edge of swamps and bogs, and see the 

 thick moss and rank grass slowly moulding away 

 beneath the water, and forming a black, soft soil, on 

 which other generations of plants live, and, perishing in 

 turn, add more and more to the ever-increasing mass 

 of dead vegetable matter. In the past, long ages ago, 

 plants and trees, giant ferns and quick-growing mosses, 

 grew more rapidly than we ever see them growing 

 now. These plants, many of them water-loving plants, 

 grew apace in the hot, steamy climates, and in dying 

 left their remains in ttie black swamps and muddy 

 meadows, and contributed vast quantities of materials 

 to our soils. Some of these old soils, made almost 

 wholly of dead plants, afterwards became Qwr coal- 

 beds ; others, no doubt, helped to form the deep 

 black soils of our prairies. Earthquakes destroyed 



