856 



MEDICAL MYCOLOGY 



ends acute or roimded, short pediceled or sessile, easily caducous, dark chest- 

 nut at maturity, 7-10.5 x 2-5/^ ; sterile hyphae septate, aerial hyphae dendroid, 

 creeping. 



Colony olivaceous, becoming very intense and finally black, filamentous 

 at first, becoming glabrous in old cultures. Colonies on Sabouraud maltose 

 have centers elevated, with radial furrows, some coremia in central portion, 

 deep olive buff to dark olive buff, more or less zonate. On Sabouraud honey, 

 center elevated, umbilieate, 4 radial furrows, from dark olive buff to dark 

 olive, diffusing Saccardo's umber into the medium. On Sabouraud glucose, 

 deep olive buff to dark olive, diffusing natal brown into the medium, reverse 

 becoming olive brown. On potato glycerol, colonies mammillate, deep olive 

 buff to dark olive buff, diffusing avellaneous or wood brown into medium. On 

 carrot glycerol, growth similar to that on potato, citrine drab to deep olive, 

 diffusing buffy brown into medium. On horse dung, small tufts, citrine drab. 

 On rice grains, olive buff. 



PHAEODICTYEAE 



Mycelium dark colored, at least in age, conidiophores either simple my- 

 celial branches or more highly specialized ; conidia more or less muriform, 

 dark colored, quite variable in form. 



Key to Subtribes 



Conidiophores on differentiated hyplial branches. 

 Conidiophores definitely differentiated. 



Conidia single on the tip of the conidiophore. 



Conidia in a head at the tip of the conidiophore. 



Conidia in chains or growing quite irregularly. 



Micronemeae. 



Macrosporieae. 



Dactylosporieae. 



AUernarieae. 



This group is largely saprophytic or parasitic on plants hence reports of 

 human pathogens should be studied very critically before they are admitted. 

 Considerable evidence has been accumulating that Alternaria (especially A. 

 tenuis) is important in some cases of allergy (see Brown 1932). 



ALTERNARIA 



Alternaria Nees ab Esenbeck, System der Pilze 72, 1817. 



Sterile hyphae creeping, septate ; conidiophores single or in small bunches, 

 septate not branched, short ; conidia inverted, clavate, usually with an elongate 

 lighter tip, muriform and darker color below, mostly joined in long simple 

 chains. 



The type species is Alternaria tenuis Nees ab Esenbeck. 



Alternaria tenuis Nees ab Esenbeck, System der Pilze 72, Fig. 68, 1817. 



Recently Borsook (1933) repeatedly isolated a fungus identified as Al- 

 ternaria tenuis Nees (Cf. Elliott, John A., 1917. Taxonomic Characters of the 

 Genera Alternaria and Macrosporium, Am. Jour. Bot. 4: 439-476, Pis. 19, 20). 

 The lesions occurred following a splinter in the hand of a Roumanian Jewess 



