The scabies epidemy being observed since 1965, had developed from persistent endemic centres and pursues continuous the cyclic course of the scabies humanis in periods of 15 to 20 years. The intracutaneous tests with antigens of Notoedres alepis show a cross antigenity with the antigens of Sarcoptes scabiei and a sensibility of patients suffering from scabies. These tests have a diagnostical value. The antigens of Notoedres alepis are free of antigens from human epidermis.--The results support the theory of immunity for the interpretation of the cyclic course of the scabies, whereas wars and social and hygienic nuisances only have a modifying influence, and promiscuity, Sarcoptotoxicity of environment and others have no deciding importance.