Numbers of Bacillus anthracis bacterial colonies, which had been allowed to grow on sheep?s 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