GASTEROMYCETES 477 



which is only partially fertile; in the columella C and in the apical, conical 

 D, it remains sterile. Perhaps the columella is analogous to C of Lyco- 

 perdon gemmatum (Fig. 300, B). 



The peripheral ground tissue, which later forms the gleba, functions 

 only a short time; long before the columella and the differentiation of the 

 outer peridium is recognizable, it is changed into the inner peridium 

 Pi. Its hyphae assume the typical periclinal direction and their mem- 

 branes thicken considerably; they remain very closely intertwined, 

 however, and form a compact membrane covering the gleba, which is 

 interrupted only at the base and top of the fructification. At the base, 

 its hyphae are lost into the undifferentiated stipe St; at the top, they 

 loosen and thereby indicate the spot K where later the peristome will 

 appear. 



The outer peridium is also differentiated into three layers, a mycelial 

 layer M, the fibrous layer F, the pseudoparenchymatous layer Ps. The 

 first and third are also present in Lycoperdon and Bovista, but the fibrous 

 layer is new. Mycelial and fibrous layers surround the whole fructifi- 

 cation. Their connection is gradually loosened so that the former may 

 be separated from the latter as a firm membrane; only at the top of the 

 fructification does the connection of the two layers continue. The pseudo- 

 parenchymatous layer is not continuous but is interrupted at the base 

 and top of the fructification where it joins with the hyphae of the inner 

 peridium. In the remaining area, the connection with the inner peridium 

 is lost. Whereas originally it was connected with it by a loose hyphal 

 tissue, with increasing age its elements were more and more separated 

 until finally, at the loosening of the pseudoparenchymatous layer, they 

 were torn apart from the inner peridium. 



At spore maturity the gleba goes through the same changes as in 

 Lycoperdon. The trama disappears and only its firmer hyphae withstand 

 disintegration as capillitium. Similarly, the more delicate elements of 

 the sterile tramal tissue, the columella and the layers S swell and 

 disintegrate, leaving only the capillitium. The hyphae of the peridium 

 become loose at the top leaving a small opening. Their membranes 

 thicken very markedly in the manner of the capillitium and in this 

 species forms a cover of the peridium which is lacking in others. 



Growth in breadth begins in the pseudoparenchymatous layer and 

 the cross-section of the large, thin-walled cells doubles. The pressure 

 thus created ruptures the peridium at the top, the point of least resistance ; 

 it splits into three layers, the mycelial layer, the fibrous and fleshy layer 

 and the inner peridium. The mycelial layer remains, as Fig. 303, B 

 shows, in the form of a subterranean, cup-like sheath whose upper third 

 has been torn into four lobes. The earlier place of fusion of the mycelial 

 layer and fibrous layer is retained; consequently the deeply split, fibrous 

 and pseudoparenchymatous layer is turned inside out at the end of 



