83 



Spores produced in oogonia, or cells whose contents are fertilized, 

 by other cells called antheridia. . Parasitic fungi spreading their 

 mycelium in the intercellular spaces of living plants. Producing, 

 besides the true spores, conidia, which are successively detached 

 like beads from the ends of branches, and are capable of vegetat- 

 ing directly, but sometimes form vegetating swarmspores. 



PERONOSPORE^:. 



Spores produced naked on the points of spicules of larger cells 

 called basids, which are sometimes exposed, and sometimes 

 inclosed in a head. BASIDIOMYCETES. 186 



Spores produced on threads. 190 



Spores produced in minute sacs or asci. 



Asci naked or arranged on an exposed surface. Discomycetes. 185 

 Asci contained in a head, or within a peridium. Pyrenomycetes. 



Fruit very small, not growing underground. 184 

 Fruit large, growing underground. 



Fruit cork-like, or woody outside, of uniform color within. Bear- 

 ing, at length, a dusty mass of spores inside. ELAPHOMYCETES. 

 Fruit veined or marbled inside. Interior wavy and deeply folded. 



TUBERACEI. 



184, Fruit head entirely closed. Growing mostly on living leaves. 

 Producing bead-like conidia as well as true spores. 



PERISPORIACEI. 



Fruit head with a mouth-like perforation. SPH.SRIACEI. 

 Fruit head opening by an irregular rupture at the top. Asci borne 

 on branched threads which stretch across the cavity of the head 

 in every direction. Growing mostly on animal substances. 



ONYGENEI. 



185. Asci produced singly on branches of the mycelium, or without a 

 mycelium. Mostly minute fungi, parasitic on living plants. 



GYMNOASCI. 

 Plant made up of black, jointed threads, bearing here and there 



sporanges or asci. ANTENNARIEI. 

 Asci in groups. 



