Symbol 



Phycomycetes 

 (Symbol J3 in Columns 18 and 19 of Field E) 



Gametes, uninucleate or multinucleate, haploid, either isogametes or 

 heterogametes; antherozoid and egg^ 



Zygote, diploid, uninucleate or multinucleate (if multinucleate, the 

 diploid condition may be uninucleate or multinucleate according to the 

 number of nuclei contributed by the antherozoid) 



Germinating zygote, haploid (i. e. , after meiosis), multinucleate, 

 forming either spores (Symbol 4) immediately from its protoplast 

 (ordinarily zoospores) or a mycelium (Symbol 5) 



Spore formed directly from a germinating zygote, haploid. 

 Includes spores which are formed from a special, limited mycelium (not 

 comparable to vegetative mycelium) produced by the germinating zygote. 

 (Use Symbol 7 for a spore from a vegetative mycelium. ) 



Young vegetative (haploid) mycelium (either nonseptate or, if septate, 

 usually having multinucleate cells), not yet producing asexual spores 

 nor gametes. ^ Formed from a zygote or a spore or a mycelial fragment. 

 (If the mycelium is producing spores or gametes, use Symbol 6 or 8, 

 respectively. ) 



Vegetative mycelium as in Symbol 5, but mature and producing haploid 

 spores 



(If the mycelium is producing gametes, use Symbol 8. ) 



Spore, haploid, uninucleate (either a motile zoospore or a nonmotile, 

 resting aplanospore), formed from a vegetative mycelium. Includes 

 conidiosporangia (= Phycomycete "conidia") and chlamydospores. 

 (Use Symbol 4 for a spore from a germinating zygote. ) 



Vegetative mycelium as in Symbol 5, but in a stage of producing sex 

 organs, antheridla and/or oogonia, instead of, or in addition to, 

 asexual spores 



2 

 Stages of maturation of gametes within the oogonium or antheridium 



Except those Phycomycetes which apparently include an alternation of generations in which the 

 diploid condition is retained from the zygote through a vegetative mycelial stage which reproduces 

 only asexually--to return to the haploid stage by producing haploid spores. In the scheme above, 

 this diploid generation could be represented only by Symbol 2; if finer distinctions are needed, it 

 will be necessary to devise a special list of life cycle stages for Phycomycete members like 

 Allomyces sp. 



'(See the footnote under the Basidiomycetes. ) 



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