EUTHALLEPHYTA EUMYCETES FUNGI 195 



EUMYCETES 



Parasitic or saprophytic plants with one or more cells, chlorophyll absent 

 with apical growth ; mycelium usually evident ; reproduction sexual and asexual, 

 generally the latter; asexual by the formation of zoospores, conidia or spores. 



PHYCOMYCETES 



Thallus generally of a single branched tubular thread; septa in connection 

 with the reproductive bodies only ; threads containing many nuclei ; reproduc- 

 tion sexual and asexual, in the latter the spores generally in sporangia (Mucor) ; 

 conidia in chains (Albugo), or at the end of the hyphae (Plasma para) ; re- 

 production sexual by copulation forming zygospores (Mucor) or oospores in 

 Plasma para and Albugo. 



ZYGOMYCETES 



Parasites or saprophytes ; mycelium branched not septate, or septa in con- 

 nection with the formation of the reproductive bodies ; reproduction sexual by 

 endospores, acroconidia, or chlamydospores. A group of fungi represented by 

 the Fly Fungus (Empusa) and Common Black Mould (Mucor). 



MUCORACEAE 



Sporangia with columella, many spored, zygospores between the threads of 

 the mycelium. Few species have the two sexes united on the same plant ; gen- 

 erally they are on the separate individuals. According to Blakeslee, Sporodinia 

 contains both sexes (homosporangic, homosporic, homophytic and homothallic). 

 Phycomyces is dioecious, the zygospores producing at germination but one kind 

 of germ tube which gives rise to a sporangium containing both male and female 

 spores, (homosporangic, heterosporic, homophytic, heterothallic) Mucor mucedo 

 has sexes separated on different individuals but two different kinds of germ 

 tubes are formed by the germination of the zygospores, (heterosporangic, heter- 

 osporic, heterophytic, and heterothallic). Zygorrhynchus is heterogamic. The 

 same author* has recently reviewed the literature. 



About 85 species widely distributed. The Phycomyces was first found in 

 oil kettles, and not infrequently in oil cakes. Sporodinia are parasitic on larger 

 fungi. Pilobolus crystallinus is common on horse manure, the conidiophore 

 being enlarged. The sporangia look like "fly specks" on the wall. This fungus 

 is not injurious. 



Mucor (Micheli) Link. Mucor. Mould 



Mycelium creeping, conidiophores simple or branched ; sporangia spherical 

 or pear-shaped ; columella well developed, wall of sporangium mucilaginous, in 

 some cases chlamydospores, or forming small chains or "cysts" ; zygospores 

 produced by the fertilization of two gametes. 



A genus of wide distribution of 50 species. The life history of a common 

 species, the Mucor stolonifer (Rhisopus nigricans) found on bread and de- 

 cayed fruits is as follows. The gray felted mycelium spreads through the 

 substratum, and on the surface small black bodies, the sporangia, are produced. 

 The conidiophore arises from the felted mycelium and bears an enlarged spher- 

 ical head, the sporangium, within which, occur the spores. On adding water 



* Bot. Gazette 1909:418. Reprint. 



