HYPHOMYCETES 541 



filaments is conclusive. Sometimes actinomycotic pus does not 

 contain granules; if the sinus be curetted, the organisms will fre- 

 quently be demonstrable in the scrapings, even though they are absent 

 from the pus. 



Mycetoma (Madura Foot). The term Mycetoma is a generic one, 

 including purulent inflammations of the foot chiefly, but also of the 

 hands and less commonly of other parts of the body. The lesions 

 superficially resemble those of actinomycosis. 



Three varieties of the disease have been described, depending upon 

 the color of the granules found in the pus the melanoid or black type, 

 the ochroid or white, and a red type which has been less thoroughly 

 investigated. 



Several organisms have been isolated from the various lesions, 

 including not only an Actinomyces (Actinomyces madurae), but a 

 mold, Aspergillus bouft'ardi, as well. 



The mutual relations of the organisms and the various types of 

 Madura foot have not been satisfactorily determined. 



HYPHOMYCETES. 



Eumycetes or Molds. The molds are a group of organisms which 

 are structurally somewhat more complex than Bacteria for, with a 

 very few exceptions, there is a physiological division of function into 

 vegetative cells which provide the nutrition of the organism and 

 reproductive cells which are concerned in the perpetuation and mul- 

 tiplication of the species. They are widely distributed in nature, 

 the majority living saprophytically upon lifeless organic matter 

 some are parasitic upon animals and plants; few types, however, 

 incite disease in man, animals, or plants. 



In human pathogenesis their activities are usually restricted to the 

 skin and adnexa, but occasionally spreading over mucous membranes 

 and even involving the respiratory tract. Among the hyphomyceal 

 diseases of man are favus, ringworm, thrush, pityriasis versicolor, 

 sporotrichosis and aspergillosis. 



The cells of molds are larger than bacteria, as a rule, measuring 

 on the average from 2 to 10 microns in diameter, and they grow into 

 long filaments or threads called hyphae, which tend to branch and form 

 intricately interwoven networks called mycelia. Like all true plant 

 cells, each hypha exhibits a clearly defined, doubly contoured ecto- 

 plasm or limiting membrane within which is confined the cytoplasm, 



