This microbe was discovered in the contents of a tubercular cavity in the lungs, and afterwards in normal sputum. It has been investigated by Gaffky. It consists of micrococci, which, when found in the living body, are arranged in fours, each group having a clear capsule around it. These groups somewhat resemble sarcinas. The bacteria have been cultivated in nutrient media, but they lose their peculiar arrangement. They have been used for inoculation in animals, and are violently pathogenic in white mice and guinea-pigs, while house and field mice and rabbits are insusceptible. The cocci are found in the blood and tissues of all organs. This microbe may possibly be the cause of pathological conditions in man, especially suppurations.