THE FUNGI 



271 



and fall vertically in the space between the two adjacent gills. 

 Buller estimates the spore discharge in Coprinus comatus, the 

 common shaggy Coprinus, to aggregate one hundred million 

 spores per hour during the period of active spore discharge, so 

 that if any considerable proportion of these spores germinated 

 and produced new plants, the world would very soon be overrun 

 with mushrooms. Most of these reproductive bodies of the mush- 

 room fail to grow, however, on account of an unfavorable environ- 

 ment, so that there is no perceptible increase of the species. 



PUFFBALLS 



The puffballs resemble the mushrooms in being saprophytes. 

 The plant is also divided, like the mushrooms and molds, into 

 an underground feeding mycelium, or spawn, and an aerial por- 

 tion which bears spores. The spawn is identical in appearance 



Spore 

 chamber 



Mycelium (spawn) 



FIG. 150. Drawing showing the external and internal structures of a puffball 



a, external view with mycelium in the soil; b, median long section showing 



gleba and peridmm; c, ripe puffball, in which the gleba is transformed into 



spores and capillitium 



with that of the mushroom, but the aerial fruit body is the sub- 

 spherical puffball seen in nature (Fig. 150). The hyphae of which 

 the puffball is composed differentiate very early into one or more 

 dense outer layers, called the peridia (singular, peridium), and an 

 inner loose mass of hyphse, called the gleba. This inner gleba 



