990 THE HIGHER BACTERIA, MOLDS AND FUNGI 



The parasite grows readily on all ordinary media. On agar it forms 

 a creamy layer, in broth a flocculent deposit. It forms gas on certain 

 sugars. Most strains do not liquefy gelatin or clot milk. The mor- 

 phology of the organism has been most thoroughly studied by Roux 

 and Linoissier. Commonly it develops as a mass of oval cells reproducing 

 by budding but often, especially in fluid media forms filaments like those 

 seen in the lesions, with terminal or lateral spores. Large globoid chlamy- 



FIG. 112. THRUSH. Oidium albicans, unstained. (After Zettnow.) 



dospores at the end of short lateral branches are also found. These charac- 

 teristics have led most authors to call the parasite a monilia. 



Monilia is a rather ill-defined genus of hyphomycetes in which 

 are included yeast-like organisms which reproduce by blastospores 

 but which also form filaments of short irregular units which are 

 easily detached. The filaments give rise to large oval cells fre- 

 quently appearing as short terminal chains which are called by some 

 conidia, by others, blastospores. Castellani includes in this genus 

 only organisms which ferment sugars with the formation of gas. 



Several authors have reported the presence of ascospores in cul- 

 tures of the thrush fungus and have classed it with the saccharom- 

 yces. Vuillemin found also endospores within the mycelial filaments. 

 It seems probable that the disease is not always caused by the same 

 organism. Fischer and Brebeck described two varieties, a large- 

 spored type with endospores which liquefied gelatine, and a small- 

 spored type, without endospores which did not liquefy. Castellani 

 concludes that several species of moniliae and also members of 

 other genera may cause thrush. On the other hand Fineman 21 

 studied five strains from thrush and found them identical. They 

 were however indistinguishable from eight strains found incidentally 



n Fineman, B. C., Jtnir. Inf. Pis., 1921, XXVIII, 185. 



