186 THE GASTEROMYCETES OF THE UNITED STATES AND CANADA 



thick and composed of several distinct layers (see below) ; surface hard, smooth (except 

 when very fresh or very old), at maturity splitting into six to many rays which expand 

 or recurve when wet and fold in again when dry, the inner layer soon becoming much 

 cracked. Inner peridium pliable, thin, sessile, depressed-globose, about 1.2-3 cm. 

 broad, surface felted and when in good condition reticulate with fibrous lines, whitish, 

 becoming gray or brownish, opening by an irregularly torn mouth which is without a 

 defined peristome. In the fresh condition the plant is tasteless and odorless. Gleba 

 pure white in youth, divided up into very small, more or less box-like regions by very 

 thin tramal plates, each chamber closely packed with the fertile, practically homogene- 

 ous tissue; this mass being made up of branching threads and small fibers bearing more 

 or less grape-like clusters of nearly spherical basidia, which are crowded amongst each 

 other, leaving only small unoccupied spaces here and there. 



Spores 4-8 to a basidium, sessile on its top and sides, reddish brown, globose, 

 distinctly tuberculate, 7 .4-10.8/1 thick including the warts. Basidia irregularly ar- 

 ranged in long strings of clusters, subspherical with a stalk, 11-15.5 x 18-24/x. Capil- 

 litium threads arising from the entire inner surface of the peridium, including the base, 

 very pale, long, interwoven, branched, 3-5.5/j thick, smooth or encrusted with granules 

 and without any obvious tapering terminals; walls very thick, so as to leave no lumen 

 in many places; no cross walls obvious. 



The plant is very persistent. Ripening in the fall, it may be found in good condi- 

 tion through the winter and spring and the shape is retained for more than a year of 

 exposure. Like many Geasters, it is loosened from the soil on expanding and may be 

 rolled about by the wind when dry, the outer layer of the rays slowly wearing away in 

 thin flakes. The range and adaptability of the species is astonishing. It is apparently 

 world wide in distribution and almost universal in habitat. Scores may be picked up 

 on a short walk among the sand dunes of the seashore, and it is among the commonest 

 fungi of the high mountains. We know of no other plant of which this can be said, 

 not even the fern Pteris. 



In a fresh button practically fully grown but still with white gleba, a section shows 

 the following characters: a very thin outer flocculent layer of delicate, loosely woven 

 fibers, which as the plant approaches maturity or is exposed, collapses almost to in- 

 visibility and soon wears away; next a strong fibrous layer about 1 mm. thick, brownish 

 toward the surface, whitish inward; next the horny layer which in immature buttons 

 is very thin but thickens toward maturity to about 0.5-0.7 mm., translucent cartilage 

 color and sharply contrasting; next a soft, pure white layer which is thickest of all 

 (about 1.5-1.8 mm.), which splits in the middle at maturity and collapses down to a 

 thin, scurfy layer on the inside of the rays and the softly felted, irregularly reticulated 

 layer on the surface of the spore sac. Under the microscope it can be seen that the 

 outer part of this layer which goes to the rays is denser, firmer, composed of fibers 

 running parallel to the surface which in the central region turn inward and become more 

 loosely woven. At the point where the turn is made the splitting takes place. The 

 part remaining on the rays forms very thin reddish flakes that soon fall off. The in- 

 nermost layer is very thin (about 0.1 mm.), translucent white, fibrous and tough; 

 basal attachment of the spore sac 1.5 cm. wide, distinctly limited by the extent of the 

 fleshy layer. At the base all distinct layers disappear into a homogeneous white tissue 

 which is about 0.7-1.5 cm. wide. While the plant is often entirely subterranean until 

 dehiscence, the mycelial attachment is confined to a basal disk one cm. or more broad, 

 from which rather numerous, small dark fibrils extend into the soil. These are very 



