Bacillus sphaericus

Anthrax, or Bacillus anthracis, is spore-forming bacteria found in soil that most commonly affects cattle.

Might Stevens have encountered spores of Bacillus anthracis during a recent hike through woods in North Carolina?

There are a number of bacilli, called acid-fast bacilli, which stain in the same way as the tubercle bacillus.

It, or a similar bacillus, is sometimes found in the sputum of gangrene of the lung.