Unit 731 - Activities

Activities

A special project code-named Maruta used human beings for experiments. Test subjects were gathered from the surrounding population and were sometimes referred to euphemistically as "logs" (丸太, maruta?). This term originated as a joke on the part of the staff because the official cover story for the facility given to the local authorities was that it was a lumber mill. In an account by a man who worked as a "junior uniformed civilian employee" of the Japanese Army in Unit 731, the term Maruta came from German, meaning medical experiment, used in such contexts as, "How many logs fell?"

The test subjects were selected to give a wide cross section of the population and included common criminals, captured bandits and anti-Japanese partisans, political prisoners, and also people rounded up by the Kempetai for alleged "suspicious activities". They included infants, the elderly, and pregnant women.