MUSHROOMS 



277 



532. ■ 



gilled 



upon it at right angles to the surface (Fig. 530). Some 

 of these put out from two to four, or in some species as 

 many as eight Httle prongs, each bearing a spore (Fig. 

 S31, s, s), while others remain sterile. The spore-bearing 

 cells are called basidia, the sterile ones, parapliyses, and 

 the whole spore-bearing surface together, the hymenium, 

 from a Greek word meaning a membrane. It is from the 

 presence of this expanded fruiting membrane that the 

 class of mushrooms we are con- 

 sidering gets its botanical name, 

 Hymenoniycetes, membrane fungi. 



395. Spore Prints. — When 



the gills are ripe they shed their 



spores in great abundance. Take 



up the pileus that was laid on 



paper as directed under Material, 



on page 273, and examine the 



print made by the discharged 



spores ; it will be found to give 



an exact representation of the under side of the pileus. 

 The hymenium is not always borne on gills, but is 



arranged in various ways which serve as a convenient basis 



for distinguishing the different orders. In the Polyporei, 



to which the edible 

 boletus belongs 

 (Figs. 533, 534), the 

 basidia are placed 

 along the inside of 

 little tubes that line 

 the under side of 

 the pileus, giving 

 it the appearance 

 of a honeycomb. 

 In another order, 



the porcupine fungi, they are arranged on the outside of 



projecting spines or teeth, while in the raorelles they are 



held in little cups or basins. 



- Spore print of 

 mushroom. 



533 534 



533, 534. — A tube fungus (Boletus edulis) : 533, entire ; 

 534, section, showing position of the tubes. 



