7fi PLECTOMYCETES [ CH - 



, 887 ZUKA, H. OberK.,urd=rAskenfruch,von/' OT ^ OT ^- K. K. zoo. 



IS 



I907 SS^CL^^^H.S. TheMorphology 



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,909 SCH.KORRA, W. Ueber die Entwickelungsgeschichte von JJfiHw. Zeits 



,9,0 ?HOM, P C 37 Cultural Studies of Species of Penicillin. U.S. Dept. Agr. 

 Animal Industry Bull. 118. 



Bureau 



Onygenaceae 



The Onygenaceae include only the remarkable genus Onygena, There 

 are some six" species, all limited in habitat to such animal substances as 

 horns, hoofs, feathers, fur and skin. This peculiarity, together with the 

 absence of conidia, the thin wall of the perithecium, and the fact of its 

 dehiscence by lobes or by a circular split, distinguishes the members 

 of the group from the other Plectascales, which they resemble in the 

 irregular arrangement of their asci. Two of the six species have sculptured 

 spores and sessile fructifications which thus approach those of the Aspergill- 

 aceae, while in the other four the spores are smooth and the fructification 

 stalked. To the latter group belongs Onygena eqidna, described by Marshall 

 Ward in 1899. The ascospores germinate only after a prolonged resting 

 period or after treatment with gastric juice ; thus treated they produce a 

 vigorous mycelium on which the ascocarp first appears as a dome-shaped 

 mass of white hyphae ; a little later it becomes covered with loose cells 

 among which air is entangled, rendering the fruit very difficult to wet. As 

 development proceeds a number of hyphae grow outwards and divide into 

 short segments, certain of which swell up and are liberated as chlamydo- 

 spores, covering the whole of the stroma with a dense powder. 



Meantime the hyphae which gave rise to these become crowded together 

 to form the pseudoparenchymatous sheath. Internally asci are produced 

 and give rise each to eight spores, but the ascus walls soon disappear and 



