In light of the '' Sonderaktion Krakau '' , a German operation in which many distinguished professors from Jagiellonian University in Kraków were arrested and sent to German concentration camps , the danger that a similar fate would befall Lwów intellectuals was very real . As a result , in July 1941 , Weigl began hiring prominent Polish intellectuals of the city for his institute , many of whom had lost work as a result of the closure of all Polish institutions of higher learning by the Nazis . In fact , soon after , the Nazis carried out a massacre of Lwów professors . Weigl managed to convince the occupation authorities to give him full discretion as to whom he hired for his experiments , even as he himself refused to sign the so-called Volksliste which would have identified him as an ethnic German ( since he was of Austrian background ) with access to privileges and opportunities unavailable to Poles . Similarly , he refused an offer to move to Berlin , direct a dedicated institute and become a Reichsdeutscher . The group of scholars hired by Weigl were often brought in by Wacław Szybalski , an oncologist , who was also put in charge of supervising the lice feeding
Sonderaktion Krakau
Sonderaktion Krakau
Feeder of lice