Plant-breeding; comments on the experiments of Nilsson and Burbank . Svalof Ex])erimentStation consists in the search for such elementary forms,and in their isolation and subse([uent comparative purifying and no fixing, or in other words, no subsequentor continuous selection is needed, provided the chosen earsare not hybridized. Man cannot originate these variations,nor can he essentially improve them. He must simply beon the alert to recognize and isolate them and to comparetheir progeny with the main strain. In the same way theproblem of corn-breeding is to recognize these elementar
Plant-breeding; comments on the experiments of Nilsson and Burbank . Svalof Ex])erimentStation consists in the search for such elementary forms,and in their isolation and subse([uent comparative purifying and no fixing, or in other words, no subsequentor continuous selection is needed, provided the chosen earsare not hybridized. Man cannot originate these variations,nor can he essentially improve them. He must simply beon the alert to recognize and isolate them and to comparetheir progeny with the main strain. In the same way theproblem of corn-breeding is to recognize these elementaryraces. All success depends upon finding the best amongthem and on thus taking complete advantage of the variabil-ity already existing in the fields. Even the races with spe-cial characters, as, for instance, those with a high yield ofoil or of protein, have, as a fact, been secured in this sameway. Corn, however, chffcrs from the other cereals in somevery important points. Two of them are now to be consid-ered. One is the open pollinized condition, and the other. Fig. 3v A. Tassel of corn, llowering and producing the anthers from thespikelets. B. Cob in the husks, producing the silks, 122 PLANT^BREEDING is the large size of the ears and their enormous number ofseeds. On a normal individual, the female or pistillate flowersare combined on the ears, and at the time of tlowcring thepistils or silks are protruded from the top of the husks. Thewind has to carry the pollen to them. The male or stam-inate inflorescences are the tassels on the top of the flower contains tliree stamens, and each tassel pro-duces about 20,000,000 to 50,000,000 grains of pollen. Byfar the largest (quantity of these is, of course, lost, being depos-ited on the foliage or falling to the ground. But a sufticientnumber are transferred to the silks to insure the completefertilization of the ears. This, liowever, is not reached atonce, but several days are needed for the process. The silksdo not al
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