130 ] The Classification of Lower Organisms 



Subclass Hemiasci or Hemiasceae, with suborder (Unterreihe) Hemiascineae, 

 and suborder Protoascineae of subclass Euasci, Engler in Engler and Prantl 

 Nat. Pflanzelfam. I Teil, Abt. 1 : iv (1897), the names not based on those of 

 genera. 

 Order Protoascineae Campbell Univ. Textb. Bot. 165 (1902). 

 Order Hemiascalcs Engler Syllab. ed. 3: 28 (1903). 



Ascomycetes whose asci develop directly from the zygotes. Two families may be 

 recognized. 



Family 1. Endomycetacea [Endomycetaceae] Schroter in Engler and Prantl Nat. 

 Pflanzenfam. I Teil, Abt. 1: 154 (1894). Family Ascoideaceae Schroter op. cit. 145. 

 Mostly saprophytes, the uninucleate or multinucleate cells of the filaments tending 

 to round up, become separate, and function as conidia; the zygotes, produced by 

 syngamy of scarcely differentiated cells, enlarging and becoming asci of 4, 8, or 

 many spores cut out by free cell formation. Dipodascus, Eremascus, Endomyces, 

 Ascoidea. The asci of the last are apparently produced asexually (Walker, 1935). 



The genus Protomyces requires mention. It is a parasite on higher plants, producing 

 walled resting spores which germinate by producing a sporangium of many spores. 

 It is chytrid-like, but its spores are non-motile. Its proper place in classification has 

 for a long time been a puzzle. 



Family 2. Saccharomycetacea [Saccharomycetaceae] (Rees) Schroter op. cit. 153. 

 CXa^?, znd iarm\y Saccharomycetes y<! inter m Rabenhorst Kryptog.-Fl. Deutschland 1, 

 Abt. 1: (1879). Unicellular, reproducing by budding, i.e., by production upon 

 the cells of outpocketings which are pinched off as additional cells, or by a sexual 

 cycle in which endospores are produced, usually by fours. 



These are the organisms which are in English called yeasts. The common bread- 

 and beer-yeast called Sac char omyces cerevisiae has a good claim to be considered, 

 economically, the most important of all "fungi." Its metabolism, in which dextrose 

 is converted to alcohol and carbon dioxide, gives a superficial appearance of sim- 

 plicity, and has attracted much study, contributing much to an understanding of the 

 genuine intricacy of energesis. 



In addition to agents of fermentation, this family includes pathogens causing 

 chronic infections of animals. These have been treated as a genus Torula, Torulopsis, 

 Blastodenna, or Cryptococcus. They have not been observed to produce endospores. 



Order 2. Mucedines Fries Syst. Myc. 3: 380 (1832). 



Order Gyjnnoascaceae Winter in Rabenhorst Kryptog-Fl. Deutschland 1, Abt. 



2: 3 (1887). 

 Suborder Plectascineae Engler in Engler and Prantl Nat. Pflanzenfam. I Teil, 



Abt. 1: V (1897). 

 Order Plectascineae Campbell Univ. Textb. Bot. 169 (1902). 

 Order Aspergilliales Bessey in Univ. Nebraska Studies 7: 304 (1907). 

 Order Gymnascales Clemens Gen. Fung. 93 (1909). 

 Order Plcctascales Gaumann Vergl. Morph. Pilze 164 (1926). 

 Ascomycetes producing cleistothecia in which the asci are scattered; mostly 

 saprophytic and producing branched conidiophores. 



The name Mucedines means molds. Under this name Fries listed twelve genera, 

 with Aspergillus Link and Penicillium Link first. The former is the evident standard 

 genus of the order. Both genera are very common and numerous in species. They arc 

 readily recognized under the microscope by the forms of their clusters of conidia. 



