Comparative Studies of Selfed Progeny and Testcross 3 Selection Methods Visual Selection Studies 20 Visual selection during line development in 21 self-pollinated species Effects of visual selection on combining ability 28 in maize MATERIALS AND METHODS 35 Plant Materials 35 Field Procedures 41 Statistical Procedures 44 RESULTS 74 Effects of Visual Selection 74 Sg lines 74 S^ line (S^ plant) testcrosses Relationships Between S^ Lines and Testcrosses Estimates of additive variance Correlations of S^ and testcross performance Selection based on S^ and testcross performance 159 DISCUSSION 169 Usefulness of Visual Selection Among and Within S.