HISTOPLASA1A CAPSULATUM 369 



chronic meningitis, whereas in Europe ulcerative lesions of the 

 skin and underlying tissues are a more common manifestation. 

 The evidence by Benham (1934) indicates that European blasto- 

 mycosis and American torulosis are identical. Freeman's (1931) 

 account of clinical appearance and pathology shows that there 

 may be chronic respiratory involvement which leads to a diagnosis 

 of tuberculous meningitis. The pathogen is presumed to enter 

 through the respiratory tract. 



The etiology of this disease remains confused. Freeman (1931) 

 indicates that several organisms may produce the same disease 

 complex. 



The pathogen is usually known as Torida histolytica or Crypto- 

 coccus hominis. It is one of the Saccharomycetaceae, having ovoid 

 to elliptical cells occurring singly or in groups and invested by a 

 thick gelatinous capsule. It forms white to yellowish white, 

 pasty, opaque colonies on agar. Its only known method of repro- 

 duction is by buds, unless the researches of Todd and Hermann 

 (1936) are confirmed. Their study of the developmental cycle 

 shows endospore formation of the type found in Debaryomyces, 

 in consequence of which they referred the pathogen to D. homi- 

 nis. It has been suggested, on the basis of priority, that the proper 

 binomial is D. neoformans. 



A generalized blastomycosis, manifest as cutaneous abscesses, is 

 caused by the closely related Blastomy ces dermatitidis, also known 

 as Gilchristia dermatitidis or Xymonema dermatitidis. 



HISTOPLASMA CAPSULATUM 



Approximately 30 years ago Darling reported the occurrence 

 among the natives of Panama of a disease characterized clinically 

 by fever, emaciation, anemia, splenomegaly, leucopenia, and ulcer- 

 ation of the nose, throat, and intestines. He was not able to iso- 

 late the etiologic agent but believed it was a protozoan, to which 

 he gave the name Histoplasma capsidatwn. Subsequently other 

 cases of histoplasmosis were recorded in widely separately places, 

 and in 1932 de Monbreun (1934) isolated and described the causal 

 fungus. In the mononuclear blood cells and lymph vessels it exists 

 as yeast-like cells with thick capsules. When the organism is kept 

 at body temperature on blood or serum media, this form of the 

 pathogen persists. When grown on other agar media, however, it 



