494 COMPARATIVE MORPHOLOGY OF FUNGI 



fundament from that of the pileus, such as we find in the gymnocarpous 

 Agaricales. The fundament of peridium and gleba shows a deeply 

 staining ring containing a small radial lacuna, below which is a cuneate 

 ring of loosely woven hyphae, the primordium of the partial veil. The 

 lacuna, which extends as a ring around the base of the columella, enlarges 

 and the hyphae lining its roof arrange their tips in a palisade which 

 gradually covers the whole cavity except its floor. The tramal plates 

 grow downward from the top of the cavity until they meet and anastomose 

 with the walls of the cavity, dividing the large cavities into smaller ones, 

 such as we have seen in Gallacea Scleroderma, and somewhat resembling the 

 growth of the lamellae or tubes in the higher Agaricales. At the same 

 time, other cavities are formed in the undifferentiated gleba above the 

 original cavity, corresponding to those formed from the inner portion of 

 the peridium in Gallacea ; but different from any structures reported in the 

 Agaricales. About the time basidia appear in the palisades of the cavities, 

 the peridium is differentiated and as the pileus expands, the furrow between 

 it and the columella widens and deepens. The partial veil makes little 

 growth after it is differentiated, and hence is torn apart and disappears 

 at maturity. A few remnants persist about the stipe, giving it a fibril- 

 lose appearance similar to that of the cortina in mature species of Cortinar- 

 ius. The columella pushes gradually up into the developing ground 

 tissue of the pileus, just ahead of the formation of cavities, reaching 

 and merging with the peridium when the fructification is about half 



grown. 



S. erythrocephalum agrees with this development in most particulars. 

 Its peridium is more highly differentiated, becoming covered with a defi- 

 nite gelatinous layer, filled with pigment granules which originally lined the 

 walls of the cells. In material collected by Zeyher at Uitenhage, South 

 Africa, and determined as S. Gueinzii, Berkeley (1843) reports a well- 

 developed volva which persists as polygonal areoles in mature specimens. 

 The spores are also said to be similar to those of Hymenogaster albus, 

 rather than the ellipsoidal, smooth or asperate spores of other species of 

 Secotium. Cytologically, the life cycle is the same as in Gallacea, all 

 portions being binucleate, with fusion of the dicaryon and meiosis in the 

 basidium and a mitosis in the young basidiospores. 



Endoptychum, similar to Secotium and often included in that genus, 

 is confined to the drier regions of the north temperate zone. The only 

 well-known species is E. agaricoides (Secotium agaricoides, S. acuminat- 

 um?), with a purely angiocarpous development similar to that of Secotium 

 (Conard, 1915; Lohwag, 1924a). The youngest fundaments of the fruc- 

 tification form a homogeneous body of tissue, surrounded by a firm 

 peridium. A closed annular hymenial cavity is developed within the 

 tissue. By increased local growth of certain subhymenial tissues, lamellae 

 with cystidia grow toward the stipe and columella. On account of the 



