3 o8 



DIVISION 77. COURSE OF DEVELOPMENT OF FUNGI. 



GASTROMYCETES. 



SECTION LXXXIX. The Gastromycetes include the chief groups of the Hyme- 

 nogastreae, Lycoperdaceae, Nidularieae, and Phalloideae ; to these are joined 

 a few smaller divisions composed partly of forms intermediate between them and partly 

 of divergent genera and some small groups. 



The compound sporophores in these Fungi spring from a simple filamentous or 

 from a compound mycelium (see page 22). They are for the most part large, often 

 very large, bodies ; Fig. 141 represents a beautifully small specimen of a small species. 

 When forming their spores they are all, with the exception of Gautieria, a genus of 

 the Hymenogastreas, receptacles or sacs entirely surrounded by a closed wall of 

 dense texture, the peridium or uterus, and usually divided inside by plates of tissue 



springing from the peridium into chambers 

 in which the hymenium and the spores are 

 formed. 



Gautieria has no peridium ; the chambers 

 in the periphery lie on the free surface and are 

 open to the outside. In all other forms the 

 peridium varies in thickness according to the 

 species and is often extremely thick ; in many 

 cases it is largely and peculiarly differentiated, 

 partly into persistent, partly into temporary 

 parts, as will be set out at greater length 

 presently. It is a general occurrence in the 

 course of this differentiation that the peridium 

 becomes strongly, often very strongly, thick- 

 ened at the base, though there are exceptions 

 to this rule, as in Hysterangium and the 

 Nidularieae. The thickened portion either 

 projects outwards in the form of a stipe 

 which bears the chambered portion, as in 



Lycoperdon and Octaviania, Fig. 141 ; or it projects inwards forming a cushion, as 

 in Hymenogaster, Rhizopogon, Geaster hygrometricus (Fig. 146), or as an elongated 

 vertical central column, as in most species of Geaster (Vittadini), the Phalloideae 

 (see pages 316. 322) and others. The point of origin of the central column is termed 

 the base, because in all cases in which the earliest states are known it corresponds 

 to the point where the compound- sporophore springs from the mycelium, and 

 generally also to the place of insertion of the full-grown peridium. In some forms, 

 as Rhizopogon and Geaster, mycelial strands run into the peridium at very various 

 and often at many points in the outer surface, and the first commencements are 

 not known ; here therefore the expression base is only applicable by analogy. 



Except in the Nidularieae and some divergent genera which will be specially 

 considered at a future time, the chambers inclosed by the peridium are narrow 

 irregularly curved and branched cavities, just large enough or too small to be seen 

 with the naked eye, and separated from one another by thin curved plates of tissue 



Fir.. 141. Octtrviania asterospertna, Vittad. Median 

 longitudinal section through a nearly ripe compound sporo- 

 phore. From Tulasne, Fungi hypogaei. Magn. 8 times. 



