Phylum Inophyta [121 



3. The zygotes giving rise indirectly to 

 conidiophores called basidia, each 

 bearing typically four conidia 



called basidiospores Class 4. Basidiomycetes. 



1. Not known to reproduce sexually Class 3. Hyphomycetes. 



Class 1. ZYGOMYCETES (Sachs ex Bennett and Thistleton-Dyer) 



Winter 



Zygomyceten Sachs Lehrb. Bot. ed. 4: 248 (1874). 



Zygomycetes Bennett and Thistleton-Dyer in Sachs Textb. Bot. English ed. 847 

 (1875). 



Class Zygomycetes Winter in Rabenhorst Kryptog.-Fl. Deutschland 1, Abt. 1: 

 32 (1879). 



Order Zygomycetes Engler Syllab. 23 (1892). 



Class Zygomyceteae Schaffner in Ohio Naturalist 9: 449 ( 1909). 



Inophyta whose zygotes are thick-walled resting cells, in germination giving rise to 

 spores indistinguishable from those produced asexually; hyphae usually without cross- 

 walls; mostly not producing fruits. The standard species is Mucor Mucedo L. 



Among the Inophyta as here limited, the Zygomycetes appear to be primitive (an 

 alternative hypothesis, that certain Ascomycetes are primitive, will be discussed be- 

 low). Traditionally, the Zygomycetes are associated with the Oomycetes. The asso- 

 ciation is probably mistaken, being based merely on similarity of body form: the 

 Zygomycetes are terrestrial instead of aquatic, produce no flagellate cells, have no 

 cellulose in their cell walls (except in Basidiobolus) , and do not produce female 

 gametes by the cutting out of cells within a cell. In later editions of Engler's Syllabus 

 (1924), one finds most of the chytrids included among the Zygomycetes, instead of 

 in their conventional place among the Oomycetes. The hypothesis thus suggested, 

 that the Opisthokonta may represent the ancestry of the Inophyta, is attractive, but 

 not to present knowledge supported by convincing evidence. Class Zygomycetes and 

 phylum Inophyta must as yet be regarded as of unknown origin and treated as isolated. 



There are some 500 known species of Zygomycetes. They form two orders. The 

 bulk of the group, and the typical examples, are order Mucorina. A minority, 

 distinguished by parasitism and by explosively discharged conidia, are order 

 Entomophthorinea. 



Order 1. Mucorina [Mucorini] Fries Syst. Myc. 3: 296 (1832). 



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



Abt. 1: iv (1897). 

 Order Mucorineae Campbell Univ. Textb. Bot. 158 (1902). 

 Order Spirogyrales (presumably in part only) Clements Gen. Fung. 12 (1909). 

 Order Mucorales Smith Crypt. Bot. 1 : 405 (1938). 

 Order Zoopagales Bessey Morph. and Tax. Fungi 117 (1950). 

 The typical Zygomycetes, mostly saprophytic, not producing explosively dis- 

 charged conidia [Piloholus produces explosively discharged sporangia). 



The asexual reproductive structures of the supposedly primitive Mucorina, as 

 Mucor and Rhizopus, are solitary globular sporangia terminal on erect hyphae. In 

 the developing sporangium, a dome-shaped basal sterile area, the columella, is set 

 apart by cleavage followed by deposition of a wall. The protoplasm above the 



