Abstract
Virus-like particles have been found closely associated with the centrioles in CHO-K1 and CHO-10 cells but not in other cell lines. They are spherical and measure 55 to 65 nm in overall diam.; their central cores of about 35 to 40 nm diam. sometimes appear hollow and sometimes dense. An amorphous matrix similar to that surrounding the centrioles is found around the particles. The possibility that they represent a type-A virus is discussed.