6th July 1944
217 Jewish people were selected from the Hungarian transports to be registered as prisoners in Auschwitz. They received numbers A-17235 - A-17451. There were 3 sets of twins amongst them, all of them were girls. They were registered with numbers A-8735 - A-8740. It is possible that some of the young and healthy people were kept alive in the camp as ‘deposit Jews’. The rest of the transport was killed in the gas chambers.
Mengele used Auschwitz as an opportunity to continue his anthropological studies and research on heredity, using inmates for human experimentation He was particularly interested in identical twins, people with heterochromia iridum (eyes of two different colours), dwarfs, and people with physical abnormalities. Mengele's twin research was in part intended to prove the supremacy of heredity over environment and thus bolster the Nazi premise of the superiority of the Aryan race. The twin studies may also have been motivated by a desire to improve the reproduction rate of the German race by improving the chances of racially desirable people having twins.
Mengele's research subjects were better fed and housed than other prisoners and temporarily safe from the gas chambers. He established a kindergarten for children that were the subjects of experiments, along with all Romani children under the age of 6. The facility provided better food and living conditions than other areas of the camp, and even included a playground. When visiting his child subjects, he introduced himself as 'Uncle Mengele' and offered them sweets. But he was also personally responsible for the deaths of an unknown number of victims that he killed via lethal injection, shootings, beatings, and through selections and deadly experiments.
Twins were subjected to weekly examinations and measurements of their physical attributes by Mengele or one of his assistants.
Experiments performed by Mengele on twins included unnecessary amputation of limbs, intentionally infecting one twin with typhus or other diseases, and transfusing the blood of one twin into the other. Many of the victims died while undergoing these procedures. After an experiment was over, the twins were sometimes killed and their bodies dissected. If one twin died of disease, Mengele killed the other so that comparative post-mortem reports could be prepared.