MOLDS AT<tt> YEASTS AND DISEASES CAUSED BY THEM 243 



doubly contoured spherical parasitic form into mycelial growth in 

 the agar hanging block inoculated with pus. The reverse trans- 

 formation of the mycelium into spherical forms was also followed 

 in the inflammatory exudate of animals inoculated with the 

 mycelial growth and finally it was shown that, by the exclusion of 

 air, the parasitic spherical form could be made to continue for a 

 time its multipHcation by endogenous spore formation in artificial 

 culture. 



Coccidiodes immitis causes a highly fatal disease of man, 

 coccidioidal granuloma, protean in its cHnical manifestations, 

 usually chronic in course and often presenting in the histology of 

 its lesions the most perfect mimicry of tuberculosis. The parasite 

 in such lesions is a spherical body 20 to 35 n in diameter, with a 

 doubly contoured wall, filled with a granular protoplasm, sopie- 

 times vacuolated, sometimes segmented. Guinea pigs are sus- 

 ceptible to inoculation. The disease seems to be confined to the 

 western hemisphere and a large proportion of the reported cases 

 have developed in Cahfornia. The mode of transmission of the 

 disease and the possible existence of the parasite in the external 

 world under natural conditions have not been ascertained. 



Bottytis Bassiana.- — This mold was shown to be the cause of 

 muscardine, a disease of silkworms, by Bassis and Audouin in 

 1837, a discovery following closely the recognition of the itch 

 mite, Sarcoptes scabei, as the cause of scabies in 1834. The in- 

 fected silkworm becomes sluggish and dies, and the aerial hyphae 

 of the fungus grow out from its surface and pinch off round 01 

 pear-shaped conidia. These spores gain the surface of other 

 silkworms or butterflies by contact or by air transmission, and 

 germinate, sending threads into their bodies. Sickle-shaped 

 spores are produced from these inside the body, and these grow 

 out into threads, forming a mycehal network throughout the body 

 of the victim and causing its death. It is possible that several 

 different species of molds may be concerned in the causation 

 of muscardine. 



The fungus is of interest because it was probably tlie first 



