610 



MEDICAL MYCOLOGY 



In Aspergillus the mycelium is mostly submerged, with only the conidio- 

 phores rising above the surface. In Penicillium both submerged and aerial 

 mycelium usually occur. The aerial mycelium is usually colorless, unless 

 colored crystals are deposited on the walls of the hyphae. The submerged 

 mycelium often shows a brilliant color. Since this is usually observed from 



Fig. 89. — Monascus ruber. l-.'f, .stages in the development of sexual organs ; 1, an- 

 theridium pusli-ed aside by young female organ ; S, female organ curving over antheridium and 

 separated from the main hypha by a septum ; 3, female organ divided into ascogonium and 

 trichogyne ; 1,, fusion of antheridium and trichogyne ; 5, later stage ; 6, early stage of perithecial 

 formation, in which the ascogonium is being envelop-ed by sterile hyphae, arising from the 

 stalk below ; 7, a wall enclosing a septate ascogenous hypha of which both the end and 

 second cells have formed asci with conspicuous nuclei. Other young asci are present, one 

 still in a binucleate condition ; 8, perithecium containing binucleate ascogenous hypha, three 

 asci having associated nuclei in various stages of fusion and one ascus with clearly defined 

 nucleus with nuclear reticulum around ascus ; 9, ascus containing four visible ascospores 

 being formed, part of a second ascus in a similar condition, and a third with a large resting 

 nucleus ; 10, two asci in a small perithecium, one showing fibers from near the wall of the 

 ascus gradually surrounding nuclei and some cytoplasm, the other enclosing ripe ascospores and 

 residual cytoplasm ; 11, almost mature perithecium showing asci and ascospores' lying free in 

 the perithecial cavity. (After Young 1931.) 



