The actinobacillus has received little, if any, consideration as an agent of human infection, though the literature abounds with reports of such infections by other organisms of Actinomycetaceae. From the first reports of the "classical actinomycosis" down through the recent cases largely attributed to the streptothrices, the confusion in nomenclature makes any definite classification difficult. The terms most frequently employed are Actinomyces, Cohnistreptothrix, Nocardia, Discomyces, and Streptothrix, with the name Actinobacillus appearing only once.1 In the last "Manual of Determinative Bacteriology" of the Society of American Bacteriologists, all of these names seem to be included in the genus Actinomyces, except Actinobacillus which is a genus by itself.2 We believe the case which we are reporting here is a true infection with Actinobacillus.
CASE REPORT
L. O. M., a boy, aged 11 months, was seen at his home, Nov. 8, 1925, and was admitted to Saint Mary's Hospital, November