. Agricultural bacteriology; a study of the relation of germ life to the farm, with laboratory experiments for students, microorganisms of soil, fertilizers, sewage, water, dairy products, miscellaneous farm products and of diseases of animals and plants. Bacteriology, Agricultural. 12 THE GENERAL CHARACTERS OE MICROORGANISMS formed backria. These are either long, coiled spirals, or very short ones, with only a single turn (Fig. 7, c). This type is of less importance than the others. Motility of Bacteria,—The next point of distinction among bacteria is b^sed upon their motility. Some bacteria
. Agricultural bacteriology; a study of the relation of germ life to the farm, with laboratory experiments for students, microorganisms of soil, fertilizers, sewage, water, dairy products, miscellaneous farm products and of diseases of animals and plants. Bacteriology, Agricultural. 12 THE GENERAL CHARACTERS OE MICROORGANISMS formed backria. These are either long, coiled spirals, or very short ones, with only a single turn (Fig. 7, c). This type is of less importance than the others. Motility of Bacteria,—The next point of distinction among bacteria is b^sed upon their motility. Some bacteria are capable of an active swimming motion, others are stationary. The motion is produced by minute, extremely delicate, vibrating hairs, called flagella (Fig. 8). The flagella are so delicate that they cannot often be seen in the Hving bacteria, and they do not stain by the ordinary method of staining. Therefore, they are never seen in the usual microscopic preparations. They may be seen by special methods, but these are so difficult that the beginner cannot use them satisfactorily. The question of their motility is, however,. Fig. 8.—Showing bacteria with flagella; a, peritrichic; &, lophotrichic; c, monotrichic. usually determined without staining, by the study of the living bacteria (Experiment No. 8). These flagella are differently dis- tributed upon different bacteria. Sometimes there is a single one on the end of a rod (Fig. 8, c)—monotrichic; sometimes a small tuft at one or both ends of a rod (Fig. 8, h)—lophotrichic; and some- times there is a covering of flagella over the whole body of the bacterium (Fig. 4, a)-—peritrichic, Spore-prodixction.—^A further point of importance in dis- tinguishing the different kinds of bacteria is spore-production, a matter which will be more fully discussed later (page 16). Many of the rod-shaped bacteria have the power of producing a tiny spore within the rod (see Fig. 11) which is more resistant to heat and drying than^
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbacteriologyagricult
