When operating on a patient for disease in the right upper abdominal quadrant, Feb. 26, 1924, I was surprised to find a small, discrete, flat piece of liver tissue lying on the surface of the gallbladder. This little body had sharp margins and, though in miniature, was veritable liver. It was attached to the gallbladder by a small mesentery, and was about 3 cm. distant from the liver proper. I gently lifted it up, tied off its mesentery with a fine catgut ligature, and removed this accessory liver intact. Recently, I have spent many hours in the Surgeon-General's Library, reviewing the literature bearing on abnormalities of the liver, and in this article I shall endeavor to give a short account of the more important observations. Abnormalities of the gallbladder might also be discussed with profit. For example, Rambault and Schachmann,<sup>1</sup>in 1882, recorded a case ot congenital absence of