CLASSIFICATION 469 



mycelium. If a few twigs bearing the fungus are placed on damp 

 moss under a tall bell-jar, their peculiar mode of spore ejection 

 may be observed. When the peridiolum is ejected, its contact with 

 the glass causes a ringing sound that can be distinctly heard by 

 anyone in the room. The peridiola are shot to a distance of one foot 

 or more, and, being ^■iscid, adhere to the glass. 



Thelebolus 



Wall of peridium single ; peridiolum solitary, protruding from the 

 apex of the peridium. 



Differs from Sphceroholus in the single wall of the peridium, and 

 in the sporidiolum not being ejected elastically. 



T. terrestris. — Peridium sessile on a broad base, hemispherical, 

 then somewhat contracted above, yellow, surmounted by the soli- 

 tary globose sporidiolum. 



Peridia gregarious, about ,'0 in. across, seated on a dense weft 

 of mycelium often extending for 1-2 inches. 



On dead wood, leaves, or on damp ground. 



Lycoperdace.e 



The most typical representatives of this family are popularly 

 known as " puff balls." Considerable diversity of structure is met 

 with in the group. In every instance the gleba or spore-bearing 

 surface is at first completely enclosed in a continuous peridium or 

 membrane. The wall of the peridium consists of two or more 

 distinct layers or strata, and the modifications that these different 

 layers undergo during development constitute the most important 

 generic distinctions. In Bovista, for instance, two distinct layers 

 are present, both are smooth, and when the fungus is nearly mature, 

 the outer layer becomes dry and breaks away in flakes, leaving the 

 inner, persistent layer intact. In Lycoperdon, the outer layer, or 

 cortex, ceases to grow and becomes rigid at an early period of growth. 

 As the inner, still living layers continue to increase in size, the 

 outer rigid layer, or cortex, becomes broken up into warts or spines, 

 which, as a rule, eventually break away, or are easily rubbed off, 

 leaving the inner layer smooth, and marked with patches in- 

 dicating the points to which the warts or spines were originally 

 attached. In Geaster, the entire fungus remains more or less 

 globose or ball-shaped until the spores are mature, when the two 

 outer layers of the peridium, adhering to each other, spht from the 

 apex of the fungus into several more or less sharp-pointed lobes 

 or rays, which spread outwards ; within these spreading lobes, 

 the third, or inner layer, remains in the form of a ball, unbroken, 

 and containing a dense mass of spores, which escape into the air 

 through a specialized mouth or opening. In some instances the two 

 layers forming the outer spreading lobes separate from each other. 



Another jieculiarity met with in tlie members of the present 



