GROUP I. THALLOPHYTA : FUNGI : BASIDIOMYCETES. 



319 



vexly outwards, bearing the endoperidium centrally, either with or without a 

 stalk, on the convex surface ; the endoperidium, which encloses the gleba, 

 dehisces with a small apical aperture. 



In Tulostoma and Battarea the tissue within the peridium undergoes differ- 

 entiation into a gleba and a stipe. When the spores are mature, the stipe 

 elongates, rupturing the exoperidium, and carries up the gleba, enclosed in the 

 endoperidium, at its apex with a portion of the exoperidium ; the rest of the 

 exoperidium remains as a volva round the base of the stipe. In Tulostoma the 

 eudoperidium dehisces at the apex forming a small aperture ; in Battarea the 

 endoperidium covering the under surface of the discoid gleba decays. 



Fam. 5. Phalloideae. The peridium is dehiscent, and the gleba becomes 

 mucilaginous. 



In the genus Ithyphallus (e.g. Phallus impudicm) the peridium consists of 

 three layers, of which the innermost and outermost are thin and firm, whilst 

 the intermediate layer is bulky and 

 mucilaginous. The internal tissue 

 is differentiated into a gleba and a 

 stipe. When the basidiogonidia 

 are mature, the stipe elongates 

 suddenly, ruptures the peridium at 

 the apex, and carries up the gleba, 

 which is now mucilaginous. The 

 elongated stipe is hollow and per- 

 forated at the apex ; the upper 

 portion of the stipe bears a thick 

 membrane attached at the apex, 

 with a reticulated surface, the re- 

 mains of the gleba. The ruptured 

 peridium remains as a volva round 

 the base of the stipe. 



In the genus Clathrus the peri- 

 dium is differentiated, as in Ithy- 

 phallus, into three layers, the 

 mucilaginous intermediate layer 

 being traversed by anastomosing 

 plates of tissue, which connect the 

 internal and external layers. From the internal layer of the peridium a capil- 

 litium is formed (something like that of some of the Myxomycetes, but much 

 stouter, see Fig. 198), which surrounds the central gleba. The gleba is con- 

 nected with the base of the peridium by a mass of cartilaginous tissue. Before 

 expansion the whole gonidiophore has a somewhat spherical form. When the 

 spores are mature, the capillitiurn expands, rupturing the peridium at the apex, 

 and lifts the gleba in its interior out of the peridium, which remains round the 

 base as a volva. The gleba undergoes mucilaginous degeneration. 



Subsidiary Group. LICHENES. A Lichen consists of a Fungus and an Alga, 

 or more than one, living in intimate connexion, and both contributing to their 

 mutual welfare that is, symbiotically (see p. 273). 



The Lichen-Fungus has always a mycelioid body, and is the constituent of 



FIG. 225. Section of compound gonidiophore 

 of Phallus impudicus : st stipe ; end endoperi- 

 dium ; ex exoperidium ; in intermediate muci- 

 laginous layer ; g gleba. (Reduced : after 

 Sachs.) 



