GASTEROMYCETEAE 



533 



coralloid, multipileate, and unipileate types. The first stands rather by 

 itself but the other three represent a gradation from coralloid to unipileate 

 types. Briefly they are as follows: (1) Lacunar type. Within the fleshy mass 

 of hyphae destined to form the gleba the tissues pull apart at various 

 places to form cavities which become lined by a palisade of basidia. A 

 modification of this type is found in scattered species, genera, and whole 

 families in which the hyphae producing the tufts of basidia instead of 

 forming an even layer around a cavity grow irregularly into it, thus form- 

 ing nests of basidia which obliterate the hymenial cavities. Such a struc- 

 ture is called "plectobasidial." (2) Coralloid type. From the basal portion 

 of the spore fruit there grow upward and outward branching masses of 

 hyphae, all within the enlarging peridium so that a coralloid structure 

 develops. The ends of these tramal branches may unite with the inner 

 surface of the peridium and spread along it to form the inner peridial 

 layer, which is therefore of tramal origin. The spaces between the branches 

 are at first continuous so that there is in fact only a single cavity very 

 much interrupted by the coral-like tramal branches which are covered by 

 a continuous hymenium. Probably the lacunar and coralloid types grade 

 into one another. Lohwag believes that the former is derived from the 

 latter. In Lycopcrdon the basal part of the spore fruit is built on the 

 lacunar plan and the upper, fertile part develops, according to Reh- 

 steiner (1892) in the coralloid manner. (3) Multipileate type. In this type, 

 clearly derived from the coralloid type, a number of the tramal branches 

 are enlarged and reaching the inner surface of the peridium spread out 

 along it, producing abundant tramal development on the under side of 

 each "pileus." (4) Unipileate type. The apical pileus of a spore fruit of the 

 multipileate plan becomes large, clothing the inner surface of practically 

 the whole peridium, the other pilei remaining rudimentary and not pro- 

 ducing fertile glebal branches. The main central stalk of the unipileate 

 type may exist as a "columella" or may elongate downward so that a 

 stipe is formed. (Fig. 171.) 



Fig. 171. Schematic representation of the basic structures of the spore fruits of 

 various Gasteromyceteae. (A) Lacunar type. (B) Coralloid type. (C) Multipileate 

 type. (D) Unipileate type. (After Fischer, in Engler und Prantl: Die Naturlichen 

 Pflanzenfamihen, Zweite Auflage, vol. 7a, Leipzig, W. Engelmann.) 



