Numbers of Bacillus anthracis bacterial colonies, which had been allowed to grow on sheeps blood agar (SBA) for a 24 hour period. Note the classical appearance exhibited in the colonial morphology including a ground-glass, non-pigmented texture with accompanying comma projections from some of the individual rough-edged colonies. There is evidence that a tenacity test had been performed using an inoculating loop, which proved positive for B. anthracis, causing the colony to stand up like