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AS pointed out by Myers and Garber (s), 8 the problem of evaluat-1\. ing pasture plants from a breeding standpoint presents several difficulties, principal of which may be the discrepancy between the behavior of spaced plants and the behavior of these same individuals when growing in sod in association with other species. Although several workers with pasture plants have used small clonal rows or beds, either clipped or grazed, to aid in evaluating the selected individuals, no previous attempts have been made, as far as the authors are aware, to ascertain the performance of individual white clover clones in association with bluegrass. MATERIALS AND METHODSIn I937, 64 plants of white clover, Tr~folium repens L., were chosen from a nursery of approximately IO,ooo spaced individuals. These plants varied in such characters as spread, height, density, size of parts, and profusion ot flowering. Cuttings from these plants were increased vegetatively in greenhouse beds during the following winter and then redivided into two-or three-node slips for rooting in soil in flats. During the first week in May I938, these rooted slips were transplanted I foot apart in each direction in plots measuring 3 X 7 feet. The soil on which these, plots were established was not fertilized in any way throughout the experiment, although it had been lightly manured the previous year when used as a hay field.The plots were arranged in a lattice design with four replications, according to Goulden's (3) field plan, except that at each "variety" location there were two plots, paired at random and planted from the same clone, one to be clipped high (cutting bar of mower set at 2 inches on level surface) and the other to be clipped low (cutting bar of mower set at I inch). In the 6-foot cultivated alley in front of each "variety" location, a single slip of the same clone was planned and allowed 'Contribution No. 26 of the U.

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Classification and inheritance in barley Species crosses 99 Simple Mendelian characters Winter versus spring habit 103 Density of the spike 103 The barley awn in relation to yield Some rye studies Wheat-rye hybrids Buckwheat Breeding buckwheat Rice Inheritance of characters CHAPTER VIII METHODS OF BREEDING SMALL GRAINS Method of keeping continuous records Ill New introductions 113 Select'on 114 Summary of methods of selection 115 Crossing 116 Technic of harvesting, thrashing, etc CHAPTER IX SOME RESULTS OF SELECTION WITH SELF-FERTILIZED CROPS Early investigators in selection of self-fertilized cereals Selection within a pure line Selection for the purpose of isolating a pure line 125 2 BREEDING CROP PLANTS times by primitive peoples who developed many varieties. As some of the varieties which were then grown are in existence today and are cultivated in some regions, a little idea of earlier work is obtained. Coming now more nearly to present times we may briefly consider the work of the Indians with maize. Piper speaks of the plan by which seeds of different colors were planted together in one hill with the thought that this method gave increased yields. It tended to keep the varieties in a heterozygous condition. During the last three or four years Squaw Flint from the Indian reservations in Minnesota has averaged as large a yield per acre at University Farm, St. Paul, as the more carefully selected varieties. These facts should help to give the student of plant-breeding some idea of the great accomplishments in plant production in earlier times and to correct possible exaggeration of relative values of the results of recent work. Present-day breeding has achieved great results and will accomplish much more; the foundation, however, was laid many years ago. THE FOUNDERS OF THE ART OF PLANT BREEDING The relation between the science and the art of plant breeding is a very interesting subject. Through many years of trials, methods are improved; and a correct knowledge of the fundamentals of the science often does not widely modify the actual practice involved. As a rule, scientific principles allow some short cuts in breeding methods and help to eliminate erroneous and useless practices. As will be constantly emphasized in this work, there is a close relation between the mode of reproduction and the methods of breeding a plant. A knowledge of sexuality was, therefore, almost a necessity before it was possible to develop the art of breeding. Sexual processes, while not thoroughly understood, were observed in animals three or four centuries B.C. by the Egyptians and Assyrians. Existence of fruit-bearing and sterile trees of the date palm was known to the people of Egypt and Mesopotamia in early times and records of artificial pollination as early as 700 years B.C. have been found (see Fig. 1). The Assyrians commonly referred to the date trees as male and female. The Greeks, however, to whom we look for early FIG. 2. Male and female flowers of date palm about two times natural size. (Photograph taken by Swingle in Sah...