THK PATHOGENIC FUNGI 983 



In the Penicillium glaucum (or crustaceum) the fertile hyphae show 

 numerous branches toward their upper extremities and terminate in a 

 radiating group of flask-shaped cells (phialides) from the tips of which 

 chains of conidia develop the structure somewhat resembling a broom. 

 Typical cultures have a dusty green color. 



The Aspergilli are equally common and troublesome contaminants. They' 

 appear on culture media as a white feltwork often thickly dotted with black 

 points becoming in older cultures diffusely black or yellow or green. The 

 conidia are born on hyphae which terminate in a large rounded head from 

 whicli phialides project in all directions. From the tips of these extend 

 chains of conidia, often so densely packed together that the supporting 

 structure is hidden and the whole appears as a spherical mass of pigmented 

 spores. These mold are active producers of oxalic and other organic acids. 

 The Sterigmocystis differs from the aspergillus in that secondary phialides 

 each bearing a chain of spores project from each primary phialide. 



Pathogenicity. Many species of these molds are pathogenic for labora- 

 tory animals if the spores are injected intravenously. A number of human 

 infections have also been ascribed to them. So-called pulmonary asperigillosis 

 is a condition clinically resembling tuberculosis, in which an aspergillus, 

 usually the species fumigatus, is found abundantly in the sputum. In most 

 cases the fungus merely invades tissue previously infected with tuberculosis, 

 in other cases (notably in the infection which has been described in the 

 pigeon feeders of Paris by Dieulafoy and by Chantemesse and Widal) the 

 disease is apparently primary and spontaneous cure may result. Madura 

 foot, a disease which will be referred to in discussing the actinomyces group, 

 has been in certain cases attributed to infection with these molds. 



Pinta or Carate, a disease of tropical America characterized by super- 

 ficial colored patches on the skin is thought to be caused in some cases by 

 aspergilli, in others by a species of trichophyton. Aspergilli have also been 

 reported as infecting the eye, nose, auditory canal and wounds in various 

 regions. 



HYPHOMYCETES 



(Fungi imperfecti) 



Most of the fungi which have definitely been shown to be the 

 cause of human disease are rudimentary types in which one can 

 detect no distinctive reproductive processes. This makes impossible 

 their classification in the well defined groups of fungi. The thallus 

 is, as a rule, without characteristic structure and reproduction is 

 by means of simple conidia. Certain types do show close analogy 

 to saprophytic fungi with specialized spores. For example, some 



