“…A low proportion were isochromatid breaks. Similar primary effects, with breakage of chromosomes in cell cultures derived from different animal species, have been found after infection with a number of different viruses, such as herpes simplex, SW 40, polyoma virus, adenovirus -12 (HAMPAR and ELLISON, 1963; MAZZONE and YERGANIAN, 1963;STICH et of., 1964;KOPROWSKI et al, 1962;YERGANIAN et al, 1962;SHEIN et ENDERS, 1963;YOGT and DULBECCO, 1963;COOPER and BLACK, 1963;PONTEN et ctl., 1963;WOLMAN et d., 1964; MOORHEAU and SAK-SELA, 1965). Further, a n extreme form of chromosome breakage with pronounced fragmentation, described as pulverization of chromosomes, has been observed by and by HARNDEN (1964).…”