74 MANUAL OF BOTANY 



gives rise to them, and remain dormant for a longer or shorter 

 period, ultimately putting out hyphae like those of the original 

 mycelium. 



The fungi have been classified in various ways by different 

 writers. The system which is now usually adopted divides them 

 into six groups as under : — 



1. Schizomycetes, including those bodies commonly spoken of as 



microbes, or bacteria. The}" are sometimes miicellular, 

 sometimes filamentous and composed of chains of cells. 

 They have no sexual reproduction. 



2. Mj^xomycetes. The body of the fungus is a plasmodium or 



aggregation of amoeboid cells with no cell-wall. They 

 produce spores, but have no sexual reproduction. 



3. Phycomycetes. These have usualh^ a mycelium composed of 



a much-branched ccenocyte with no septa. They are often 

 erroneously described as unicellular, a condition which, 

 however, does occur in some cases. They reproduce 

 sexuall}' and asexually, zoospores and ordinary non-motile 

 spores occurring in different orders. The sexual reproduc- 

 tion is a process of conjugation or fertilisation, leading to 

 the recognition of two groups accordingly, the Zygomycetes 

 and the Oomycetes. In the former the zygote is a zygo- 

 spore, in the latter an oospore. 



4. Ascomycetes. The coenocj'tic structure is found in this 



group also, but the whole plant is usually not a single 

 coenoc3"te, but incompletely septated, forming a nmnber of 

 them. The female organ is a carpogonium, containing no 

 differentiated gamete ; the sporophyte is inconspicuous, but 

 represented by the so-called fructification. 



5. ^cidiomj'cetes. The mycelium has the same structure as in 



the last group. There is no sexual reproduction known. 

 Several kinds of spore are borne. There is an elaborate 

 structure produced called an cecidiiim, which may possibly 

 represent the sporophyte, but the homologies are doubtful. 



6. Basidiomycetes. The mycelium is much like those of the last 



two groups. No sexual reproduction is known. The 

 mycelium produces a massive structure, on certain parts of 

 which the spores are produced b^- abstriction from special 

 cells, known as basidia. 



Sub-Class I. — Schizomycetes. 

 The members of this group are very small, and almost struc- 

 tureless. The unicellular forms have various shapes, some being 



