Abstract During the past year the writer has had the opportunity to review the literature on poultry coccidiosis and its possible relation to an infection found in sparrow-like birds and, at the suggestion of Prof. Wm. A. Riley, has examined the intestinal contents of nearly one hundred English sparrows from the neighborhood of Minneapolis, Minnesota. It is the purpose of this note to report briefly upon the findings of previous writers and to give a short account of the observations made at Minesota. In spite of the fact that the infective organism of coccidiosis of the fowl has been known for some time and its life-cycle thoroughly worked out there is frequent question raised as to the method of its dissemination in nature. While it is generally accepted that control of this disease lies in the adoption of adequate sanitary measures, there is a widespread belief that some one or more . . .