1. The differential diagnosis between diphtheria and other diphtheroid (pseudo-membranous) inflammations of the upper air-passages can only be positively established in doubtful cases by the presence of the Klebs-Loeffler bacillus Author(s): De Roaldes, Arthur W. (Arthur Washington), 1849-1918, author Publication: New Orleans : [publisher not identified], 1894 Subject(s): Diphtheria -- diagnosisDiagnosis, DifferentialCorynebacterium diphtheriae -- isolation & purification