False colour scanning electron micrograph (SEM) of a colony of Neisseria meningitidis (the meningococcus), the species of non-motile, non- capsulate, aerobic, Gram-negative bacteria causing meningitis. Individual cocci are usually arranged in pairs, each one concave on the side facing its partner. N. meningitidis is an obligate human parasite & the cause of meningococcal (cerebrospinal) meningitis, the inflammation of the connective tissue membranes lining the brain, which occurs sporadically or in epidemics. In temperate climates most epidemics have occurred in closely packed communities - wartime barracks, for example. Magnification: x6000 at 35mm size.