. Agricultural bacteriology. Bacteriology, Agricultural. 44 MORPHOLOGY OF BACTERIA Others consider there to be a relationship between the richness of the cell in granules and its virulence. Hill, however, considers that, inasmuch as nitrates increase the nitrogen assimilated by Azotobacter and the number and size of the volutin bodies, they bear some relationship to the organisms' power to fix nitrogen. Although it. FIG. 12.—Successive stages in division of Bacillus diphtherice, showing relation of line of division to metachromatic granule. Continuous observation of living bacillus drawn witho
. Agricultural bacteriology. Bacteriology, Agricultural. 44 MORPHOLOGY OF BACTERIA Others consider there to be a relationship between the richness of the cell in granules and its virulence. Hill, however, considers that, inasmuch as nitrates increase the nitrogen assimilated by Azotobacter and the number and size of the volutin bodies, they bear some relationship to the organisms' power to fix nitrogen. Although it. FIG. 12.—Successive stages in division of Bacillus diphtherice, showing relation of line of division to metachromatic granule. Continuous observation of living bacillus drawn without camera lucida. (Williams.) is quite possible that they may possess various functions in differ- ent organisms, the majority of them would seem to be, as suggested by Mev_pr, reserve food materials which occur in the cytoplasm of the cells of various bacteria. They are most numerous in rapidly growing young cultures and usually disappear when the food becomes scarce. FIG. 13.—Types of bacterial spores. (Kendall.) Spores.—Bacteria possess the power of mobilizing the vital parts of their body into a much smaller space than they occupy during their normal life. They exclude all of the excess moisture and sur- round themselves by a tough resistant coat. In some respects this form of the organism resembles the seed of the higher plant and we speak of it as a spore. While in this stage they will with- stand many conditions which would quickly prove fatal to growing bacteria. Some of them can withstand the temperature of boiling water for many hours, or they may survive treatment with strong carbolic acid. For the time being they have lost the power of mul- tiplying, but they are still alive and if they are brought into appro- priate surroundings they will change back Into normal bacteria just as a kernel of wheat changes into the young plant when placed in moist soil. It is indeed fortunate for mankind that but few of the disease-producing organisms form spores. There are, ho
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