Magnified 1796X, this 2002 scanning electron microscope (SEM) image revealed some of the ultrastructural morphology exhibited by three Hartmannella vermiformis amoeba cysts. The amoeba assumes the cystic stage of its life cycle under harsh conditions such as drought, or when there is an accumulation of toxins in its environment, which can reduce its metabolic needs. Under these circumstances, the protozoan produces a protective coat and goes dormant to wait for better conditions. CDC/Dr Rodney Donlan 2002