310 PATHOGENIC YEAST-LIKE FUNGI 



intracerebrally into mice. When so injected the pathogen produces 

 typical gelatinous masses of budding cells in the meninges and within 

 5 to 15 days (depending upon the dosage and virulence of the strain) 

 causes death of the animal. 



Taxonomy. The thick capsule found in old cultures of Crypto- 

 coccus neoformans has been interpreted by some investigators as an 

 ascus, and the small cell within the capsule as an ascospore. The 

 fungus therefore was transferred to the genus Debaryomyces.^° We 

 have been unable to verify these observations. The manner of origin 

 of the structures in question, their morphology, and their staining 

 reactions seem to identify them rather with capsular material, stored 

 food, and other vegetative structures. The large hyaline body which 

 is conspicuous in many cells seems to originate by the coalescence of 

 many small spherules and this material takes the fat stain. Until 

 additional evidence bearing upon this point is brought forward it 

 seems proper to refer the fungus to the imperfect yeasts under the 

 name C. neoformans. 



Distribution. The disease is widely distributed around the world 

 and it is probable that apparent geographical localization is due 

 actually to recognition rather than to an actual limitation of dis- 

 tribution. 



Habitat in Nature. At about the same time that Busse and 

 Buschke isolated this fungus from human lesions Sanfelice isolated 

 it from fruit. Strains closely resembling it and believed to be aviru- 

 lent strains of the species have been isolated from the surface of 

 normal skin.* It seems probable that the natural habitat of the 

 fungus is the surface of fruit and that from this and other vegetable 

 material it may be transferred often to man. 



Moniliasis. The commonest of the mycoses caused by yeast-like 

 fungi is moniliasis, caused by Candida albicans {Monilia albicans). 

 This fungus is primarily a parasite of the mucous membranes. Thus 

 thrush occurs most frequently in the mouth, and not uncommonly in 

 the vagina (in pregnancy). It may also extend through the gastro- 

 intestinal tract, and is very commonly found in sputum, although 

 the level of infection in such cases is often unknown. Primary in- 

 fections of the bronchi and lungs not associated with thrush have 

 been reported, but the role of the fungus, whether primary or second- 

 ary, is a disputed point. In moniliasis the infections may involve 

 the skin, producing eczema-like lesions of the moister parts such as 

 the webs of the fingers, the groin, sub-mammary folds, and any skin 

 crevice in which there are moisture and maceration. In all these 

 conditions it may be questioned whether the fungus is of primary 



