The micrococcus tetragenus is currently regarded a harmless, saprophytic organism as far as man is concerned, as may be seen by reference to any of the ordinary text-books of bacteriology. During late years, however, occasional observations have shown that it may assume a pathogenic rôle and acquire a considerable degree of virulence for man. Among the researches which have brought out the occasional pathogenic rôle of this microbe may be mentioned those of Gaffky, of Teissier, and others. The most recent contribution to the study of this organism is by Bosc and Gallavielle.1
These authors observed three cases of human infection with the micrococcus tetragenus, one of which is especially interesting. It concerns a man, 45 years old, who entered the hospital in a condition of great feebleness, accompanied with dyspnea and a yellowish expectoration which emitted a gangrenous odor. Examination showed a dull area in the lower left