This volume includes the papers of the Mayo Clinic for 1911 and naturally a large variety of subjects is considered. The greater part of the book is devoted to the alimentary canal and the genito-urinary organs. Ductless glands receive a comparatively small share of attention. Of special interest is the group of papers on diagnostic aids, including radiographic diagnosis and the use of the cystoscope. The paper by Dr. J. H. Selby, on "Collaboration in Radiographic Diagnosis," is profusely illustrated. The papers on the ductless glands are by Dr. Charles H. Mayo, with one on "Parathyroids and Their Surgical Relations to Goiter" by Drs. Charles H. Mayo and Bernard F. McGrath. The book closes with an obituary of William Worrell Mayo, the father of the Mayo brothers, who died March 6, 1911, at the age of 92.