[Species of the Bacillus strain: macroscopic and microscopic morphology].

Between October 2001 and January 2002, the Microbiology Group of the Instituto Nacional de Salud processed 705 envelopes under suspicion of harboring anthrax spores. We present photographs of cultures and slides prepared from them of Bacillus species to be used as reference material for the accurate macroscopic and microscopic identification of the agent found in samples.