622 MEDICAL MYCOLOGY 



cells; stalks not septate or septate, usually enlarging- upward and broadening 

 into ellipsoid, liemispheric, or globose fertile vesicles bearing phialides either 

 parallel and clustered in terminal columns or radiating from the entire sur- 

 face; phialides in either one or two series; conidia varying greatly in color, 

 shape, and markings, successively cut off from the tips of the sterigmata by 

 septa and forming unbranched chains arranged in radiate heads or packed 

 into columnar (cal3q:)trate) masses; perithecia found in some species, unknown 

 in others, cleistocarpous, thin-walled, producing asci and ascospores within a 

 few weeks ; sclerotia regularly found in some strains, occasionally found in 

 other strains and not found in other closely related strains, mostly spherical 

 or subspheric, commonly composed of thick-walled cells which appear to be 

 filled with stored material. 



The species of this genus are predominantly saprophytic, but certain spe- 

 cies are quite regularly pathogenic. Perhaps the organ attacked most com- 

 monly is the lung, where symptoms clinically resembling those of pulmonary 

 tuberculosis are produced, but tubercles are not produced in the lungs and the 

 conidia are abundant in the sputum, while no trace of Mycolactermm Uiber- 

 culosis is found. Most of these cases have cleared up on treatment with potas- 

 sium iodide. They seem especially abundant in regions of high humidity. 



The natives among the Watusi make use of the pathogenicity of some 

 species of Aspergillus in an interesting way, according to Mattlet (1924). When 

 they wish to wreak vengeance on some one, they exhume a corpse of a person 

 recently dead of a pneumomycosis, remove the lungs, desiccate them, and mix 

 the powder in a banana beer. Evidently the Aspergillus is not killed by this 

 process and the recipient wastes away with aspergillosis, without suspecting 

 the cause. 



The species attacking the lungs have been reported to attack other in- 

 ternal organs, especially the kidneys, of experimental animals. The older 

 literature is very well summarized by Renon (1897), Lang & Grubauer (1923), 

 and Perin (1925). 



The species centering around A. nidulans have been frequently found in 

 mycetomas, usually producing the black grain type not essentially different 

 clinically from lesions produced by Madurella (see p. 680). Finally, there are 

 many saprophytes centering around A. niger but including representatives of 

 most of the other groups, which are found in the external auditory conduit, 

 more rarely in the nasal sinus, or other situations. These species, probably 

 primarily saprophytes, have found favorable conditions for growth in the 

 cerumen and, under ordinary conditions, are harmless beyond causing me- 

 chanical irritation. A few cases have been reported where virulence seems 

 greater, and some damage was done to the surrounding tissues. A few species 

 have been reported as attacking the nails. Ballagi & Laubal (1933) have 

 shown that certain species are capable of producing crusts and scales in cu- 

 taneous inoculation and abscesses in subcutaneous inoculation in the guinea pig. 



