The spindle-celled tumours which can be produced in mice and rats by subcutaneous and intraperitoneal injections of fatty media containing 1:2:5:6-dibenzanthracene have been described elsewhere (1, 2). Transplantable tumours produced in this way have now reached the 47th and 28th grafted generation in mice and the 27th and 26th grafted generation in rats. To widen the field a test was made on fowls. Circumstances were not favourable to a large scale experiment of this nature, and therefore the following account has reference to two birds only. These were young adult, white Wyandotte hens.1 Technique 1:2:5:6-dibenzanthracene was dissolved in lard (4 mg. in 1 c.c.) by heating the hydrocarbon in the fraction of lard liquid at 37°: (a) in the earlier part of the experiment, on a hot plate at a temperature which was not measured exactly at the time, but was probably between 160° and 190°; (b) later, in an oven at 110°. The experiment was begun on July 27, 1931, each fowl receiving 3 c.c. of the preparation into the right pectoral muscles and a similar amount subcutaneously into the left pectoral region. These injections were repeated on August 1st and 10th of that year and on March 3rd, 1932. Five days later, that is to say eight months after the first dose had been given, one of the fowls died and was found to be free from any tumour.