The occurrence of double gall bladder in man has been recognized since 31 B.C., when Pliny described a case in a sacrificial victim, and the first case was recorded in medical literature by Blasius, in 1674. The number of cases reported in the modern literature totals less than forty. In 1926, Boyden reviewed the literature and recorded twenty cases and there have been additional case reports by Nichols, Climan, Cave, Hayes, Slaughter and Trout, Weiss, Wilson, and Gross, who, in 1936, published a comprehensive review of the subject of anomalies of the gall bladder and duct. Only eight cases are recorded which have been demonstrated roentgenologically and on account of the rarity of the condition it seems justifiable to report the following case. Mrs. H. J. M., widow, aged 70 years (referred by A. E. Gauthier, M.D.), complained of dull aching pain in the left lower quadrant, and pain and tenderness over the left sacro-iliac joint. Several years ago a diagnosis of low grade chronic cholecystitis had been ma...