Guderain recognised the importance of tanks © This doctrine integrated the operational-level ideas taught by Schlieffen with the tactical concepts developed during World War One. And as military technology, including that of tanks, motor vehicles, aircraft and radios, was developed during the 1920s and 30s, so it was grafted onto this doctrinal framework.
German doctors performed a variety of experiments on prisoners at Auschwitz. SS doctors tested the efficacy of X-rays as a sterilization device by administering large doses to female prisoners. Carl Clauberg injected chemicals into women's uteruses in an effort to glue them shut. Prisoners were infected with spotted fever for vaccination research and exposed to toxic substances to study the effects. In one experiment Bayer, then part of IG Farben, paid RM 150 each for 150 female inmates from Auschwitz (the camp had asked for RM 200 per woman), who were transferred to a Bayer facility to test an anesthetic. A Bayer employee wrote to Rudolf Höss: "The transport of 150 women arrived in good condition. However, we were unable to obtain conclusive results because they died during the experiments. We would kindly request that you send us another group of women to the same number and at the same price." The Bayer research was led at Auschwitz by Helmuth Vetter of Bayer/IG Farben, who was also an Auschwitz physician and SS captain, and by Auschwitz physicians Friedrich Entress and Eduard Wirths.
By July 1944, Germany was losing the war; the SS began closing down the easternmost concentration camps and deporting the remaining prisoners westward. Many were killed in Auschwitz and the Gross-Rosen concentration camp. Schindler convinced SS-Hauptsturmführer Amon Göth, commandant of the nearby Kraków-Płaszów concentration camp, to allow him to move his factory to Brněnec in the Protectorate of Bohemia and Moravia, thus sparing his workers from almost certain death in the gas chambers. Using names provided by Jewish Ghetto Police officer Marcel Goldberg, Göth's secretary Mietek Pemper compiled and typed the list of 1,200 Jews who travelled to Brünnlitz in October 1944. Schindler continued to bribe SS officials to prevent the execution of his workers until the end of World War II in Europe in May 1945, by which time he had spent his entire fortune on bribes and black market purchases of supplies for his workers.