fever; and when epidemics of erysipelas have involved certain states or areas, it has been noted also that nearly every obstetrical case developed puerperal septicemia. =Etiology.=--There is more than passing interest connected with this last statement. It is now definitely established that the infectious organism is a _streptococcus_ which is allied to, if not identical with, the streptococcus pyogenes, the ordinary pyogenic organism of this form. This specific organism has been separated, studied, and its role assigned by Fehleisen, and the organism is frequently called _Fehleisen’s coccus_. Preserving always its morphological characteristics, it acts, as do many other pathogenic organisms, within wide limits in virulence. Cultivated from some cases, it scarcely seems infectious, while from others it is fatal. =Pathology.=--The disease manifests a tendency to travel _via lymphatic routes_. As long as it is confined to the skin and superficial tissues it has the appearance of an acute dermatitis. When it migrates deeper it generally leads to suppuration, another reason for believing that the streptococci of erysipelas and of pus production are the same. In the affected and infected area the minute lymphatics will be found crowded with the cocci, which are seen much less often in the small bloodvessels; also in the tissues beyond the apparently infected area they may be found dispersed less freely. The bacterial activity seems most active along the advancing border of the superficial lesion. Here the phenomena of hyperemia and phagocytosis are most active. Even in the vesicles that are characteristic of the disease the organisms may be found. The _discharges_ from this region are _infectious_, and caution should be observed in dressing such cases. A finger pricked by a pin from a dressing may subject the individual to loss of life. The _dressings_ containing the discharges should be _burned_ immediately. The path of infection is usually through a wound, and as soon as discovered a case of erysipelas should be separated from all surgical cases, or if the erysipelatous patient cannot be isolated, he should be removed from proximity of other wounded individuals. Erysipelas which follows injury, however slight, is termed _traumatic_. The terms “idiopathic” or “spontaneous” should be restricted to those cases in which the path of infection is not discovered.