Department of General Medical Microbiology and Laboratory of Virus Etiology of Tumors, N. F. Gamaleya Institute of Epidemiology and Microblology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. D. Timakov.) Translated from Byulleten'' Éksperimental''noi Biologii i Meditsiny, Vol. 74, No. 10, pp. 60–62, October, 1974.