. Bacteria in relation to soil fertility. Soil microbiology; Bacteriology, Agricultural. 28 BACTERIA AND SOIL FERTILITY o® 0©©e 0(D oocdgogR. are extremely small. Even the largest are not visible to the naked eye. The smallest are beyond the range of our most povi^erfiil microscopes. The Pfeiffer bacillus, the organism which v^^as thought to cause influenza, is one of the smallest organisms knov^n. It is a rod-shaped organism, and if placed end to end £fty thousand of them would be required to reach one linear inch. It ' O ffi OO CD® 0000 ^^^^^ ^"q^"^" ^^''''^ fifteen thousand t
. Bacteria in relation to soil fertility. Soil microbiology; Bacteriology, Agricultural. 28 BACTERIA AND SOIL FERTILITY o® 0©©e 0(D oocdgogR. are extremely small. Even the largest are not visible to the naked eye. The smallest are beyond the range of our most povi^erfiil microscopes. The Pfeiffer bacillus, the organism which v^^as thought to cause influenza, is one of the smallest organisms knov^n. It is a rod-shaped organism, and if placed end to end £fty thousand of them would be required to reach one linear inch. It ' O ffi OO CD® 0000 ^^^^^ ^"q^"^" ^^''''^ fifteen thousand ty- phoid bacilli to reach an inch. The organism causing re- lapsing fever is one of the largest known, and of these it would require fif- teen hundred t o reach one inch. We often magnify bac- teria one thousand times, and then they appear as dots under the microscope. If we would magnify man to this extent he would be a giant indeed—six thousand feet tall and fifteen hundred feet wide! In a sample of milk containing a billion bacteria in one cubic centimeter there is less than one-thousandth of its volume bacteria. Or, a little globe of bacteria no larger than a drop of water would consist of fifty billion bacteria. Movement.—If one places a handful of hay in a bottle con- taining beef tea and allows it to stand in a warm place for twenty- four hours and then examines a drop of it under the microscope It will be found to be filled with living organisms. One notices that all of the particles within the drop are moving^—even the small particles of hay. There is a great difference, however, in the way in which they move—some swing back and forth, while others are seen to move swiftly across the field and out of sight. All of the bodies which are thus seen to move rapidly are bacteria which have the power of movement. By appropriate methods it IiG. —Successive steps in the formation of the various groupings of the cocci, i, streptococcus. 2, micrococcus, with ce
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbacteriologyagricult
