Five fields with different soils were investigated; the land being described as follows: “Field No. 1 is a black loam containing considerable humus; field No. 2 is similar to field 1 but contains more humus; field No. 3 is a thin soil with clay gumbo subsoil; fields Nos. 4 and 5 are black loams, but not as rich in humus as either No. 1 or No. 2.” The average bacterial contents of the several fields are given as follows: Field No. 1 33,931,747 per cubic centimeter. “ No. 2 53,596,060 “ “ “ “ No. 3 78,534 “ “ “ “ No. 4 8,643,006 “ “ “ “ No. 5 3,192,131 “ “ “ “The crop records of these fields for the past ten years indicate that the crop yield has been (more or less?) directly proportional to the bacterial content of the soil of each field; field 2 has produced the largest yield, field 3 the least.” Unfortunately no chemical analyses of any of these soils are communicated; but at the request of the writer samples of the soils of the first three fields were sent from the Kansas station for humus determinations (courteously made by Dr. H. C. Myers), which gave the following results: Field No. 1 2.19% of Humus. “ No. 2 3.07% “ “ “ No. 3 1.85% “ “ While these humus-percentages are not directly proportional to the bacterial content, a favoring effect of high humus-content is clearly shown. The bacterial and the humus-content of these soils are sensibly, even if not directly, correlated; which might reasonably be expected, since the organic matter and the humus are the bacterial food. The investigation also showed wide differences in the bacterial content of the same soil when different crops were growing on it. Thus in samples taken on Aug. 15, there were found in the first twelve inches of a black loam soil bearing timothy and clover, 1,380,000, in the same with alfalfa and clover, 21,091,000, with maize from one to over two millions. In soils from the western part of Kansas, the bacterial content of the same crops was much less (as doubtless is the humus-content), and it is noteworthy that the prairie buffalo grass shows throughout a relatively high bacterial content in the first foot of the soil, ranging next to alfalfa. The root bacteria living on the legumes will naturally increase the bacterial content of the soils on which they grow, more than plants which, like maize, do not directly utilize bacterial action.