148 



INFECTIONS CAUSED BY MOLDS 



mentally, but actually are not ef- 

 fective in the direct transmission of 

 coccidioidomycosis in man. Segre- 

 gation of patients is not necessary. 

 The nuclear condition was first 

 described by Emmons '^ who showed 

 that the very numerous nuclei, 

 which frequently lie in a peripheral 

 zone of protoplasm, are typical of 

 those found in other fungi. There 

 is a distinct nuclear membrane en- 

 closing small amounts of baso- 

 philic material and a deeply stain- 

 ing nucleolus. The ultimate spores 

 were described as usually uninu- 

 cleate. Baker, et al.,^ reported that 

 they may be multinucleate. The 

 number of nuclei per spore prob- 

 ably depends upon whether or 

 not progressive cleavage proceeds 

 within the sporangium to the nor- 

 mal final stage of subdivision of 

 the protoplasm. 



Morphology in Culture. When 

 pus containing Coccidioides is 

 planted upon agar the fungus grows 

 in a very different fashion. The 

 recently liberated spores, large veg- 

 etative cells, and sporangiospores 

 still within the unruptured sporan- 

 gium germinate at once by the de- 

 velopment of hyphae. If, however, 

 the material is incubated under 

 anaerobic conditions on special me- 

 dia there may be a limited devel- 

 opment of the parasitic growth 

 phase. When grown on American 

 Sabouraud agar at 30° C. spores be- 

 gin to form in most strains in about 

 8 days. Some of the aerial hyphae bear specialized side branches 

 which are about twice the diameter of the hyphae from which they 



Fig. 75. Cultures of Coccidioides 



immilis. From C. W. Emmons, 



Mycologia, 34, 460 (1942). 



