He proposes , based on a reexamination of the evidence and symptoms , that the Black Death may actually have been an epidemic of pulmonary anthrax caused by Bacillus anthracis .
Twigg also shows that the common theory of entirely pneumonic spread does not hold up .
Twigg proposes , based on a reexamination of the evidence and symptoms , that the Black Death may actually have been an epidemic of pulmonary anthrax caused by Bacillus anthracis .
Twigg also shows that the common theory of entirely pneumonic spread does not hold up .