GASTEROMYCETES 375 



with other families. Usually the entire structure enclosed 

 within the peridium consists of plates of tissue whose free 

 surfaces are covered with the hymenium ; the entire mass 

 is here called the gleba. The plates forming the gleba 

 have precisely the same structure as the gills in Agaricineae. 

 There is a central trama bounded 'on either side by a 

 denser subhy menial layer, from which the elements of the 

 hymenium basidia and paraphyses originate. These 

 plates anastomose at numerous points, the result being a 

 sponge-like or cavernous structure, the walls of the cavities 

 bearing the hymenium. The plates in all families except 

 the Phalloideae are attached on all sides to the inner 

 surface of the peridium. In some families a large number 

 of long, tapering, simple, or branched hyphae, collectively 

 constituting the capillitium, and having to do with the 

 dispersion of the spores, are present in the gleba. These 

 capillitium threads originate from the hyphae of the trama, 

 and may be considered as homologous with cystidia, so 

 frequently met with in the Basidiomycetes. 



In the Lycoperdaceae, at a certain stage of development, 

 after the formation of the spores, the entire mass of the 

 gleba presents a water-logged appearance. This is due to 

 the deliquescence of the elements of the hymenium 

 basidia and paraphyses and the tramal plates, the spores 

 and capillitium threads alone remaining. Eventually these 

 become dry, and form a pulverulent mass, consisting of 

 spores and capillitium threads. In the Nidulariaceae, or 

 'bird's nest' fungi, the tramal walls split and become 

 hardened and permanent, enclosing the spores that were 

 borne on the wall of the cavity. There are thus as many 

 of these sealed-up portions, called peridiola, as there were 

 originally cavities in the gleba. Conidia are unknown. 



