16 COMPARATIVE MORPHOLOGY OF FUNGI 



surrounded by a cell wall in the Phycomycetes, and by the limitation of 

 the diplonts to the zygote, in whose germination meiosis occurs ; thus the 

 zygote is also gonotocont. The Ascomycetes are distinguished by 

 the more highly developed thallus and, in typical forms, by the develop- 

 ment of the zygote to a typical mycelium with meiosis shifted to special 

 reproductive organs; in the Ascomycetes into "sporangia" with free cell 

 formation, the asci; in the Basidiomycetes into "conidiophores" with 

 exogenous abscission of spores, the basidia. 



Possibly in time it will be desirable to place at the beginning still a 

 fifth class, the Myxomycetes, as these may be basically separated from 

 the Archimycetes. 



