|Bacteria that are spherical in shape are classified as
coccus (singular) or cocci (plural). Four examples of cocci are shown here at 1000
X magnification: Staphylococcus , Micrococcus , Streptococcus and Sarcina. Staphylococcus
and Micrococcus tend to form grapelike clusters,
while Streptococcus aligns in chains. Sarcina
divides into three planes, forming eight cells arranged in a cube.
In the two-dimensional views shown here only the front four cells are
visible, appearing as four cocci aligned in a cube (a tetrad).