. Bacteria in relation to plant diseases. Bacteria; Plant diseases. 182 BACTERIA IN RELATION TO PLANT DISEASES. ments were not very numerous, and, especially, were not very long-continued. Basing our conclusions on Hunger's experiments with tomato roots, we may assert with some degree of confidence that an unwounded root is impervious to this organism, but it does not appear to be equally certain that the disease can never begin in the sub-stomatal chamber. So far, however, as we yet know definitely, infection takes place only through wounds. In one of the writer's hothouse experiments, a pota
. Bacteria in relation to plant diseases. Bacteria; Plant diseases. 182 BACTERIA IN RELATION TO PLANT DISEASES. ments were not very numerous, and, especially, were not very long-continued. Basing our conclusions on Hunger's experiments with tomato roots, we may assert with some degree of confidence that an unwounded root is impervious to this organism, but it does not appear to be equally certain that the disease can never begin in the sub-stomatal chamber. So far, however, as we yet know definitely, infection takes place only through wounds. In one of the writer's hothouse experiments, a potato plant grew to maturity in health in the same pot with one which became badly diseased (in leaves, stems, and tubers) as the result of a pure- culture inoculation, but here insects were kept off. Exclusive of variable degrees of virulence on the part of the parasite and of individual or varietal resistance on the part of the host, the progress of the disease on attacked plants in the field must vary to a large extent with fluctuating temperature and rainfall. Rainy weather favors the disease, beyond question. So does moist soil. Under the equator, with rain every day, one might expect the disease to be much more rapidly fatal than in a cooler, drier climate, and such appears to be the case. According to Mr. Irons, of Porto Rico, Solatium mammosum is resistant to this disease. The Seed and Plant Introduction No. 24650, supposed to be this plant, bears small yellow gourd-like fruits having a white, tough, inedible flesh and small brown seeds. The specimen fruit seen by the writer was globose and about 2 inches in diameter. It is thought that the egg-plant and tomato might be grafted upon it, but I believe we shall find eventually more practical methods of dealing with this disease. SYNOPSIS OF INOCULATIONS. The following is a summary of all inoculations made by the writer and his assistants with Bacterium solana- cearum, so far as records were kept and are now available, except
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