l66 SAPROPHYTIC FUNGI 



There is also a complicated method of conjugation 

 which is comparatively rarely met with and will not 

 be described here. 



Other Saprophytic Fungi. — There are numerous other 

 forms of saprophytic fungi, including many with com- 

 plicated reproductive bodies (" fruit bodies "), of which 

 the common mushroom (Agaricus campestris) is a 

 good example. The mycelium lives in the humus of 

 the soil, particularly in well manured pastures, and 

 resembles that of Mucor in a very general way, except 

 that it is septate, as are all the higher fungi. The 

 mushroom itself is the fruit body, which arises first as 

 a small weft of hyphse forming a portion of the fila- 

 mentous mycelium. This increases in size by constant 

 branching and grows into a small very compact nodule, 

 which increases in size and complexity, becoming 

 differentiated into a short stalk and an arched top. 

 Finally it grows up above the soil by the rapid elonga- 

 tion of the hyphse forming the stalk and expands the 

 umbrella-shaped pileus ' or top of the mushroom. From 

 the tips of the hyphse which run at right angles to 

 the surfaces of the plalelike " gills " on the underside 

 of the pileus there are budded off spores, • four or two 

 from each hypha tip, each formed on a small projecting 

 point. The enormous number of spores produced by a 

 single mushroom may be gauged by placing a ripe 

 pileus, detached from its stalk, underside downwards 

 on a piece of white paper and leaving it for a day or 

 two. On gently removing the pileus a pattern of the 

 gills will be found designed in streaks of microscopic 

 spores on the paper. 



«- " A woven hat." 



