Partial characterization of a cubic Bacillus phage. Can. J. Microbiol. 24: 986--993. Phage Bam35 is an icosahedron of about 63 nm in diameter. It has a double capsid with spikes at the vertices, and a tail which seems to appear upon nucleic acid ejection. The phage contains DNA and, probably, lipids which seem to be located in the inner coat. The phage is Bacillus-specific, UV- and lipase-resistant, and sensitive to heat, chloroform, and ether. The latent period is 50 min and the burst size is 39. Page Bam35 belongs to a new virus group which includes a phage of B. anthracis and four phages of gram-negative bacteria harboring drug-resistance plasmids.