The Papers of the Michigan Academy of Science, Arts and Letters is an annual volume of papers published under the joint direction of the Council of the Academy and of the Executive Board of the Graduate School of the University of Michigan, and edited by Paul S. Welch and Eugene S. McCartney. The agreement to publish jointly was an opportunity to establish closer relations between the University and the Academy, thus contributing to higher scholarship and original investigation. This volume from the 1922 annual meeting includes an array of papers on Biology, Economics, Geology, Meteorology, Psychology, Sanitary and Medical Science, and Zoology.