YEASTS 275 



imperfecti group. The initial infection usually takes place through 

 some slight abrasion of the skin and from thence spreads along 

 the line of the lymphatics. Lesions have been recorded in the 

 larynx, pharynx, and muscle and bone tissues. Sporotrichosis 

 appears in the past to have been frequently confused with syphilis 

 because the condition readily yields to treatment with iodin com- 

 pounds ; mercury salts have no curative effect. 



Thrush. Infection, which is most frequent in young infants, 

 occurs as white patches of fungoid growth on the tongue and fauces 

 and may extend into the esophagus. General infection has been 

 reported, with abscess formation in the various internal organs. 

 In lesions and in cultures the fungus shows characteristics both 

 of the molds and yeasts, and it is probable that it occupies a posi- 

 tion intermediate between the two forms. The yeast-like por- 

 tions are oval in form, averaging about 5.5 p long and 4 /* in 

 diameter, while the thread formations vary greatly in length and 

 thickness. Several varieties of thrush fungus are thought to 

 exist, although their classification at present is by no means clear. 

 The name monilia Candida has been suggested for the group. The 

 term in common usage is Oidium albicans. 



BLASTOMYCETES 



Yeasts, like molds, have been studied in the past mainly because 

 of their economic importance; for many centuries their role in 

 the brewing and baking industries has been recognized. The 

 main characteristics of the yeasts is their mode of reproduction 

 by budding, hence their name of blastomycetes or " budding 

 fungi " in contrast to that of molds, hyphomycetes, or " thread 

 fungi." Nevertheless no strict separating line can be drawn 

 between the two groups since, as already stated, forms exist which 

 possess characteristics of both groups. 



Ordinarily yeast cells are oval in shape, each cell possessing 

 a more or less definite nucleus and surrounding wall of cellulose ; 

 they vary in size from 1 /* in diameter in old cultures to giant 

 cells which may have a width of 40 /*. During the process of 



