BA SIDIOM YCE TES 



393 



FIG. 321. Cogrinus stercorarius Fr. Longi- 

 tudinal section of the end of a gill in com- 

 plete spore-bearing. t, trama; /, sterile 

 palisade cells ; b, basids with spores ; e, 

 cystids (x 300). (After Brefeld.) 



they are termed ^///y or lamella in the AGARICINI,/W^ or tubuli in POLY- 

 PORE^E, and teeth in the HYDNE^E. In many of the forms the hymenium 

 is exposed from the first ; in a series 

 of others a membrane (velum partiale] 

 connects the edge of the pileus all 

 round with the stalk, and on its rupture 

 by the extension of the pileus, part of it 

 is left attached to the stalk, when it is 

 termed the annulus or ring (fig. 320), 

 though this does not occur in all cases. 

 In a third series a membrane (velum 

 universale or volvci} (fig. 31 8) encloses 

 the whole sporophore, pileus and 

 stalk alike, and in the species be- 

 longing to Amanita, a sub-genus of 

 Agaricus, both velum universale and 

 velum partiale are present. In these 

 latter cases, therefore, in which a 

 membrane is present, 

 the sporophore differs 

 from the truly gymno- 

 carpous forms. The de- 

 velopment of Amanita 

 is especially noteworthy, 

 since the gills are not 

 developed on the free 

 inner surface of the 

 pileus, but during an 

 early condition from 

 tissue common to both 

 stalk and pileus. 



Immediately beneath 

 the hymenium is a layer 

 of tissue called the sub- 

 hy menial layer, distin- 

 guished from the rest of 

 the tissue of the sporo- 

 phore by the greater 

 density of the ramifica- 

 tions of the hyphae and 



by the more abundant FIG. 322. Polyponis igniarhis Fr. Transverse section of the 



under surface, h, the plexus of hyphae forming the walls be- 

 Contents. tween the pores ; s, the hymenium ( x 270). (After Luerssen.) 



