148 



MEDICAL MYCOLOGY 



The cytology and synonymy of this genus are very puzzling. As originally 

 described by Stiles, the spore initials and spores are uniformly scattered 

 throughout the ascus. The original descriptions of Posadasia by Wernicke 

 and Posadas are essentially similar. Then in a case from the Argentine Chaco, 

 reported by Mazza & Parodi, Fonseca noted that in spore formation, the 

 ascospore nuclei migrated to the peripheral layer of the protoplasm as they 

 do in the Protomycetaceae (Fig. 23) and are separated by radial cleavage 

 planes (Fig. 23, 3, 4) followed by periclinal planes until two or three layers 

 of protospores are produced (Fig. 23, 5, 6). The protospores then form groups 

 of 2-16 spores, which finally expand and fill the whole central vacuole as they 

 increase in size. Almeida (1932) working with a strain from Omaha, Nebraska, 

 D. Spring 1091 found a similar condition in the host tissues. "Whether this 

 condition exists in all the North American Strains of Coccidioides and has 



Fig. 23.- 



-Coccidioides immitis (Pseudococcidioides Mazsai), development of asci in tissues. 

 (After Fonseca, in Mazza & Parodi 1928.) 



been overlooked by North American workers or whether it constitutes a real 

 difference between the North and South American species is still an unsolved 

 problem. Unfortunately apparently none of the Argentine organisms has 

 been cultivated so that we can compare cultural characters. Since Posadasia 

 esferiforniis, the organism of Wernicke and Posadas, and Pseudococcidioides 

 Mazzai of Mazza & Parodi, came from the same region, it is likely that they 

 are identical but different from Paracoccidioides hrasiliensis with which it was 

 formerly confused by Morris Moore and myself. Much more cultural and 

 cytologic study will be necessary to solve the problems of synonymy presented 

 by this family. Clinically the three groups produce similar lesions. 



Coccidioides immitis Stiles in Rixford & Gilchrist, Johns Hopkins Hosp. 

 Kept. 1 : 209-268, 1896. 



Coccidioides pyogenes R-ixford & Gilchrist, Johns Hopkins Hosp. Kept. 1: 

 209-268, 1896. 



