TETRAGENUS. 445 The organisms are fcnmd in small numbers in the heart's blood, but are numerous in the spleen, lungs, liver, and kidneys. House-mice and field-mice are comparatively immune ; dogs and rabbits are also highly resistant. Guinea-pigs sometimes die from general infection, though sometimes local abscesses may be the only result of subcutaneous inoculation. The tetragenococci are of no special importance in human pathology, but probably hasten the tissue-necrosis in tuberculosis pulmonalis, and may aid in the formation of abscesses of the lung and contribute to the production of the hectic fever.