That clover has no power in itself to gather atmospheric nitrogen, and that the bacteria do have power to feed the clover plant with nitrogen gathered from the air is very easy to demonstrate. It is one of the regular laboratory practices of the students in soil fertility in the Agricultural College to make this demonstration. Plate 1 is an illustration of such student work. The two pots which are shown were provided with all elements of plant food, excepting the one element nitrogen. Thus far the two pots are exactly alike. Each contains no nitrogen, as indicated by the label “No N.” Each pot is planted with the same number of red clover seeds. To the right-hand pot, however, some bacteria (“Bac.”) were added, while none were added to the left-hand pot. These bacteria were obtained by taking about one pound of soil from a clover-field where abundance of tubercles were found on the clover roots, adding this soil to about one quart of pure water, shaking for a few minutes, allowing the soil to settle, then taking a small quantity of almost clear solution, and adding it to the pot which we wished to inoculate with the red clover bacteria. Aside from the addition of these microscopic bacteria to the right-hand pot, these two pots were treated exactly alike throughout the experiment. It will be plainly seen that where the bacteria were added the clover was furnished with sufficient nitrogen to make a strong and luxuriant growth, while without the bacteria the clover (in the left-hand pot) only germinated and made what little growth it could with the small amount of nitrogen contained in the seed. This result is the difference between success and failure of the clover crop. [Illustration: PLATE 1. RED CLOVER: EFFECT OF BACTERIA. NO NITROGEN IN THE SOIL OF EITHER POT.] In general the clover bacteria are well distributed over the northern and central part of Illinois, but we now have some very strong evidence that they are not well distributed in some soils of large area in southern Illinois. There is also some evidence that they were not originally present even in the soils where they are now found in great abundance; and, furthermore, it seems very probable that these bacteria may cease to live in a soil where they have once been present, provided clover is not grown on the land for several years.