480 COMPARATIVE MORPHOLOGY OF FUNGI 



The middle core layer appears almost reniform in cross section. It 

 consists of a smooth tissue of slender, ramose hyphae which form club- 

 shaped basidia at their ends. 



The sterigmata are laterally inserted at unequal heights. Numerous 

 unbranched, thick-walled, undulate hyphae, the capillitium threads, grow 

 out from the core fibres. The basidia degenerate and only the capilli- 

 tium and the ochraceous spores remain in the peridium. At maturity, 

 the stipe elongates to 3 to 6 cm., the peridium tears at the spot where a 

 small cavity is formed by the drying of the stipe covering (Fig. 305, B) 

 and the gleba, together with the peridium, rises above the ground. During 

 the winter the outer layer of the peridium becomes loosened with bits of 

 earth adhering like scales, exposing the inner, lighter-colored layer (305, 

 A, left) whose opening was originally closed by a solid plug, the dried 

 upper core layer. 



The stipe is still more strongly developed in the predominantly 

 subtropical Battarrea, which is insufficiently known. Here it attains 

 a length of over 20 cm. so that the fertile portion, consisting of endoperi- 

 dium and gleba, projects above the ground like the pileus of a small 

 agaric. The peridium is circumscissile, the edges roll upward and back- 

 ward exposing a narrow ring of capillitium and spores. As these are 

 carried away by the wind, the drying action of the latter cause the edges 

 of the peridium to shrivel and roll up more, exposing more spores. This is 

 continued until the upper half of the peridium has shriveled and blown 

 away and there remains only a shallow cup of the lower half containing 

 a few spores, which are finally washed away by rain. 



Sphaerobolaceae. — In this family, the cosmopolitan Sphaerobolus 

 stellatus has been investigated (E. Fischer, 1884; Rabinowitsch, 1894; 

 Pillay, 1923; Walker, 1922, 1927; Walker and Andersen, 1925). 



The fungus grows on rotting wood preferably. The mycelial strands 

 are surrounded by an upper brownish (Fig. 306, OR) and a lower white 

 rind (Fig. 306, UR) and possess a comparatively loose core. At the point 

 where the fructification will arise, one or rarely several tissue bodies are 

 differentiated from the core. Each of these divides into a looser ground 

 tissue (Fig. 306, GF) and a firmer gelatinous rind which itself differentiates 

 into two layers, a narrow intertwined outer and a looser inner layer (Fig. 

 306, GR and IR). Only in the interior of this body is the true fructifi- 

 cation laid down as a more solid tissue (Fig. 306, SA) and always at the 

 upper edges of the rind. Generally a single fructification develops in 

 each tissue body, occasionally two. 



On further growth, the fructification arches over the rind layer of 

 the tissue body and that of the mycelial threads; when these layers dis- 

 integrate, the fructification appears above the mycelial threads (Fig. 307, 

 2) . It is differentiated into peridium and gleba. The first is composed of 

 four layers: the gelatinous mycelial layer M (which biologically corre- 



