1. Maize originated in Mexico from one of three possible progenitors: teosinte grass, pod corn, or an unknown common ancestor. 2. Ideal maize plants have upright leaves to increase photosynthesis, an extended grain filling period for uniform maturity, and cobs with over 15 rows and potential for multiple cobs. 3. Breeding objectives include increasing yield through hybridization, improving resistance to pests like stem borers and diseases like mildews, and raising protein and oil content by enlarging the embryo.