Glynn Gorick: : "Winter Wheat" The painting follows from right to left the growth stages of a crop of winter wheat. Wheat has been cultivated for thousands of years and has become one of the world's principal food sources. The leaves harness sunlight energy to make food which is stored in seeds. A single seed is shown using this store to make new roots and leaves. There is a change of scale from top to bottom, moving from the earth's atmosphere and coastal outline down to the microstructure of top soil. The soil crumbs consist of of large sand grains and minute particles of clay. The lower left corner shows a single clay particle magnified; it is made of quartz crystal. Thin films of water and air pockets in soil are also shown. Large scale agriculture can lead to soil erosion and also threatens the environment with its high inputs of fossil fuel and agro-chemicals. Each growing season, the bottom left part of this picture will "vanish" - the wheat seed to the grain silos, and, irreversibly, twice the seed's weight in top soil lost to wind and water erosion.