CHAPTER XXXVIII 



ASCOMYCETES AND BASIDIOMYCETES 



Preliminary — Classification — Protoascomycetes — Saccharomycetales — Sac- 

 charomycetaceae — Endomycetaceae — Euascomycetes — Gymnoascacese — 

 Aspergillaceae — Pyrenomycetes — Basidiomycetes — References. 



PRELIMINARY. 



This chapter includes an account of the fungi parasitic on man 

 which belong to the Ascomycetes. These fungi are characterized 

 by their mode of reproduction — viz., by spores originating inside 

 special cells called asci. The spores (ascospores, endospores, 

 gonidia) inside the asci are generally four or eight or a multiple of 

 eight. While these fungi live a parasitic life, no a^ci are found, 

 and reproduction takes place by germination and conidia. The 

 fungi belonging to this order are often pleomorphic, their morpho- 

 logical characters changing according to the medium on which they 

 live. 



Classification. — The Ascomycetes are divided into subclasses as 

 follows : — 



A. Asci with varying number of spores, usually numerous — Hemiasco- 



mycetes. 



B. Asci with a definite number of spores : — 



I. Asci separate or scattered — Protoascomycetes . 

 II. Asci approximate, usually forming a hymenium — Euascomycetes. 



SUBCLASS PROTOASCOMYCETES. 



This subclass contains a single order, the Saccharomycetales. 



ORDER SACCHAROMYCETALES. 



This order is divided into two families as follows: — 



A. Vegetative cells single or loosely attached in irregular colonies — 



SaccharomycetacecB. 



B. Vegetative cells forming a mycelium — EndomycetacecB . 



FAMILY SACCHAROMYCETACEiE Rees, 1870. . 



Definition. — Protoascomycetes with vegetative cells single or 

 loosely attached in irregular colonies; mycelium not usually 

 developed; asci isolated, not diEerentiated from vegetative cells. 



Remarks.- — These organisms are generally round or ovoid cells, 

 presenting a cell wall of single or double contour ; the internal proto- 

 plasmatic mass often shows granules and vacuoles. During active 



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