HYPHOMYCETES 615 
monly of other parts of the l)o(ly. 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 melanoifl 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 madurse), but a 
mold, Aspergillus bouffardi, as well. 
The mutual relations of the organisms and the various types of 
IVIadura 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 hyphce, 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, 
which is usually coarsely or finely granular. In the lower forms, 
Phycomycetes, each hypha is a unicellular multinuclear cell, which 
may be branched; in the high forms, Mycomycetes, the filaments 
are multicellular, each cell being separated from its fellows by distinct 
septa. A nucleus is demonstrable in a majority of the molds and it 
is probable that it is present in all. 
Reproduction.— The reproductive cells of the lowest and simplest 
forms are scarcely differentiated morphologically from the vegetative 
cells, indeed in some instances the distinction has never been made. 
The hyphffi break up and the fragments give rise to new colonies. 
Reproduction in the Phycomycetes, of which the widely distributed 
1 Oppenheim: Arch. f. dermat. u. svph., 1904, 71, 209. Babes: Comnt. rend. 
Soc. de bioL, 1911, 70, 73. 
