FILAMENTOUS AND BUDDING FUNGI. 341 



in addition, other molds be present, a pure culture can be 

 readily obtained by injecting the fungous mass into an 

 animal. The body of the animal at once differentiates 

 pathogenic and nonpathogenic molds, inasmuch as the 

 latter are destroyed with certainty. In spite of this distri- 

 bution of the pathogenic molds, mycoses are not common 

 in the animal kingdom. Spontaneously they occur rela- 

 tively seldom. Only in the lungs of birds are fatal asper- 

 gillus-mycoses and mucor-mycoses found at all frequently, 

 so that a certain susceptibility must be assumed for this 

 particular tissue, and which, otherwise, is generally wanting 

 in the animal body. 



Of pathogenic yeasts but a small number are thus far 

 known. Experimentally in animals they induce local sup- 

 puration, tumor-like swellings, and at times septic manifesta- 

 tions. 



DISEASES IN HUMAN BEINGS INDUCED BY FILA- 

 MENTOUS AND BUDDING FUNGI. 



DERMATOMYCOSES (PARASITIC DISEASES OF THE SKIN). 



Favus. The cause of favus was recognized by Schonlein 

 in 1839 as a filamentous fungus, which, in his honor, has 

 been named achorion Schdnleinii, and which was the first of 

 all organized causative agents of disease discovered. The 

 disease is characterized by a peculiar crust or scutulum. On 

 microscopic examination this is found to consist of a layer 

 of cornified epithelial cells, beneath which there is a mass of 

 fungous elements, in the form of concentrically arranged 

 mycelial threads, which give off conidia toward the center 

 of the favus-body. The center consists of conidia alone ; 

 in addition bacilli and cocci are always found. If a frag- 

 ment of this scutulum be examined in water or in glycerin, 

 the mycelia will be recognized as numerously partitioned or 

 segmented ramifying filaments of varying thickness. The 

 Conidia are of variable form and size, roundish, oval, angular, 

 in part provided with a yellowish nucleus, in part without 

 a nucleus, but with granular turbid contents. This fungus, 

 which from its form belongs to the oidium-group, is the 

 cause of favus. It is found in association with both favus 

 of the hairy scalp and in portions of the body free from 

 hair, and with favus of the nails. It has been grown in 



