The organism was observed both within and outside of neutrophils. It grew in chains, especially in tissue, but also appeared as single cells in secretions. Ducrey consistently observed this organism from a cleansed soft chancre, in pus from an unruptured bubo, and in the deep portion of an abscess. Since he was unable to culture the organism in vitro, he used serial cutaneous inoculations to establish the specificity of the infectious agent. His observations were confirmed by Krefting in 1892 and also by Unna in 1892 (as cited in reference 160). There is some controversy concerning the first culture isolation of Haemophilus ducreyi. Sullivan (160) attributed the first cultures of the bacillus of Ducrey to Lenglet in 1898 and Bezancon, Griffin, and LeSourd in 1900. However, Istamanoff (131) and Akspianz (38) have been credited with earlier isolations.