146 



SYSTEMATIC BOTANY. 



drying and rupture of the surrounding tissue. The basidia, 

 upon each of which four or more spores are borne, are 

 the rounded or elongated terminal cells of internal hyphse- 

 branches. The outer wall (peridium) of the sporocarp 



ruptures irregularly ia 

 the common Puff-ball 

 {Lyeoperdon) ; but in 

 the Earth-star (Geas- 

 ter), where it consists of 

 two layers, the outer, 

 dense layer splits from 

 the top into segments, 

 which re-curve and ex- 

 pose the inner and 

 more delicate layer. 

 This, in turn, ruptures 

 somewhat irregularly, 

 and allows the escape 

 of the spores. The 

 Giant Puff-ball (Lyeo- 

 perdon giganteum) is a 

 very common and edi- 

 ble species. 

 ^^ 2. Hymenomy- 



cetes. The sporocarp, in the Fungi of this order, is 

 composed of parallel, vertical hyphse, which grow up- 

 wards, and (as in Agarious) bend out laterally, or send 

 out lateral branches at the top, to form the umbrella-like 



Fig. 261. A Mushroom {Agaricus fihalhides) ; /, the entire plant ; //, section of 

 stem, or stipe; III, gills, in transverse section; IV, longitudinal section, showing 

 the gills, or lamellae; V, a single lamella, moderately magnified; VI, a portion of 

 the hymenium, highly magnified; VII, two hasidia, with sterigmata and spores; 

 /, pileus, or cap ; /, lamellae ; h, hymenium ; i, trama ; ^, hasidia ; sjp, spores ; 

 sii sterigmata. 



