12 SOILS 



dropped, perhaps many hundreds of miles away 

 from the place where it was picked up. Rocks 

 that could nave come only from the mouth of Lake 

 Huron are found in the drift or glacial soils in Ohio. 

 Rocks from Ontario are found as far south as 

 Kentucky. Great masses of ice were stranded 

 here ana there over the land. The streams of 

 water resulting from the melting of the ice still 

 further mixed the rocks, and the soils that the 

 glacier had ground from the rocks. 



The result of this ice sheet is the endless variety 

 of soils that are found in the North. Most of the 

 soils of that part of the northern United States that 

 was covered by the great glacier were made by this 

 agency. They are technically known as "drift" 

 soils. Where parts of the ice sheet settled and 

 melted away there were formed "morains" or 

 "drumlins," the long, rounded knolls so common 

 in northeastern United States. Since the time 

 when this ice sheet covered our land, moving water 

 has still further shifted and mixed soils, rounded 

 the knolls and deepened the gullies. But most of 

 the great variety or soil and diversity of contour in 

 this region is due to the scouring, crushing, mold- 

 ing, transporting and distributing power of the 

 great glacier. Small glaciers, performing exactly 

 the same work, may be seen to-day in the Alps, 

 Alaska, and other frigid regions. 



ANIMALS AS SOIL BUILDERS 



Animal life contributes much more to the build- 

 ing of soils than seems possible at first thought. 

 Eventually every animal and insect returns to the 

 soil, from which it came. The addition of animal 

 matter to the soil is not nearly so evident as the 



