[The morphology of a nocardia asteroides-bacteriophage (author's transl)].

The morphology of a new bacteriophage isolated from Nocardia asteroides has been investigated by negative staining. The percent results suggest a model which is valid for many phages. The head of the bacteriophage has the shape of an icosaeder with a diameter of about 420 AU. It probably contains a spherical core which is surrounded by a capsid of 15 AU thickness. A flexible non-contractible tail is connected by a collar to one of the head's edges. Its length is about 1400 AU and its diameter 60 AU. The tail shows a cross striation with a periodicity of 40 AU and a channel. At the distal side it passes over into a conical end structure. Conforming this morphological criteria the new bacteriophage belongs to the group B of Bradley.