1.The chorio-allantoic membrane of the developing chick was successfully inoculated with a seven year old culture of Histoplasma capsulatum.
2.Eggs were incubated 12 days and observed 6 days after inoculation.
3.The macroscopic appearance of the lesion showed a thickened, yellowish-gray plaque with a peripheral opaque region.
4.Microscopically, there was a marked reaction in the ectoderm, mesoderm, and the underlying entoderm.
5.The cellular response consisted of the appearance of large numbers of fibroblasts, monocytes, leucocytes, red blood cells with a marked eosinophilia.
6.The organism showed a conversion into yeastlike cells analogous to the formation of arthrospores and oidia.
7.The ascus-like cells, stalagmospores or aleuriospores became converted into many yeastlike cells which seemed to indicate that they are most likely ascus-like structures, probably of a degenerate nature.