From Spore to Mushroom 



A small portion of section of gill 

 (highly magnified) 



leaving a ragged edge to the cap, and a ring or annulus of veil 



around the stem. The gills of the Agaricus are not fastened to 



the stem, but are rounded off at 



the end near the stem, while 



others, between the long ones, 



extend from the edge of the cap 



only far enough toward the stem 



to fill up the angles formed by 



the long gills. 



The surface of the gills is the 



fruiting portion of the mushroom. 



It is here that the spores are 



formed. 



The structure of the fungus 



plant up to this point has been 



similar throughout. A loose tangle 



of threads underground formed the myce- 

 lium — the food provider. A more closely 

 matted tangle above ground formed the 

 stem and cap and veil, and even the central 

 part of the gill — the fruiting parts of the 

 plant. 



On the surface of the gill a difference 

 in structure is found, which will be clearly 

 understood from a picture of a thin section 

 cut across a gill. 



(i) The central portion of the gill is 

 made by loosely tangled mycelium threads 

 (tr) draping themselves in thin plates from 

 the surface of 

 the cap. 



(2) Just outside of this loose 

 mycelium, on either side, are layers 

 of short cells (c), which bear club- 

 shaped bodies standing out over 

 both surfaces of the gills (b). 



(3) Each club bears two slen- 

 der processes (st) at the free end, 

 and each process bears a spore 

 (sp). 



13 



Corn smut 



Leaf rust on Hepaiica triloba 



