ENDOMYCETALES 



127 



Ascospores, cucullate, saturnine. 



Mycelium multinucleate, conidia produced, ascus many-spored, proliferating. 



Ascoideaceae. 

 Mycelium uninucleate, degenerating to sprout mycelium; conidia not differentiated; 

 ascospore number usually 4 or fewer; not proliferating. 



Endo'mycetaceae. 

 Ascospores hemispheric or angular; sprout mycelium uninucleate; ascospores 4 or fewer. 



Pichiaceae. 

 Ascospores ellipsoid or spherical. 



Mycelium multinucleate, ascus resulting from copulation of two hyphal tips. 

 Ascus many-spored. Dipodascaceae. 



Ascus 8- or 4-spored. Eremascaceae. 



Mycelium uninucleate, usually sprout mycelium, asci resulting from copulation of two 



cells or from parthenogenesis or apogamy. Saccharomycetaceae. 



No trace of copulation; asci many-spored, rarely reduced to 8; mycelium often scanty 

 in the tissue but then developing readily in culture; asci usually thick-walled, 

 often differentiated as a resting spore, usually abundant in host tissue, rare 

 in culture. 

 Ascospores developing directly and filling the ascus. Coccidioideaceae. 



Ascospores developing in tetrads about the wall of the ascus. Protomycetaceae. 

 Ascospores developing directly, but reduced in numbei', not filling the ascus, mycelium 

 developing in host tissue. Taphrinaceae. 



Fig. 13. — Spore shapes in the Endomycetales. J, Nematospora; S, Coccidiascus; S, Mono- 

 sporellaj ■'/, Schwanniomyces ; 5, Nadsonia; 6, Williopsis ; 7, S, Pichia; 9, Guilliermondella ; 10, 

 Endomyces ; 11, Saccharomyces. (After Guilliermond 1928.) 



Spermophthoraceae. — In 8'permophthora Gossypii on cotton, the mycelium 

 is nonseptate and coenocytic. It produces gametangia with numerous fusiform 

 gametes (Fig*. 14, 1). After the dehiscence of the g-ametangium, the gametes 

 fuse in pairs, and the resulting zygote germinates immediately by a septate, 

 uninucleate, diploid mycelium (Fig. 14, 2-7). The asci are borne directly on 

 this mycelium without crozier formation (Fig. 14, 8). The ascospores are 

 fusiform, but smaller and shorter than the gametes. The differentiation of 

 gametes is suggestive of remote derivation from tlie Oomycetes rather than 

 from the Zygomycetes or Mucorales, as suggested by Gaumann (1926). In 

 neither group is there any structure in any way comparable to the diploid 

 ascogenous mycelium of this family. 



