Improvement in the Chemical Composition of the Corn Kernel -- Fifty Generations of Selection for Protein and Oil in Corn -- Nitrogen Fractions of the Component Parts of the Corn Kernel as Affected by Selection and Soil Nitrogen -- Results of Long-Term Selection for Chemical Composition in Maize and Their Significance in Evaluating Breeding Systems -- Genetic Variability After 65 Generations of Selection in Illinois Oil and Protein Strains of Zea mays L -- Seventy Generations of Selection for Oil and Protein Concentration in the Maize Kernel -- The Structure of the Corn Kernel and the Composition of Its Different Parts -- Ten Generations of Corn Breeding -- The Mean and Variability as Affected by Continuous Selection for Composition in Corn -- Front Matter