So far as we are aware, no case of carcinoma arising in the lung of the domestic fowl has been recorded. The following case is, therefore, of some interest:In 1929, on a farm in Victoria, Australia, I found one day the dead body of a second-year Black Orpington lying on its side, with blood around its beak. This fowl had been ill for some days. I performed an autopsy at once.The right lung and most of the left lung were replaced by a white mass resembling fibrocaseous material. The heart and pericardium were grossly normal. The stomach and intestine and other abdominal organs were also unchanged, except for a small white nodule of growth under the surface of the liver, about 3 mm. in diameter. The specimens were placed in dilute alcohol and taken to the Pathology Department of the University of Melbourne for microscopic study by Professor P. MacCallum and myself.