30 Mas see. — A monograph of 
wall of the umbo) remaining in apposition until the period 
of dehiscence, when by a process to be afterwards described, 
separation of the teeth takes place, the margins and inner 
surface of each being covered with red powder. 
The endoperidium, as already stated, is not differentiated 
from the exoperidium at the base. There is no trace of a 
columella springing from the basal portion of the inner wall 
of the endoperidium. The innermost layer or spore-sac is 
at first composed of hyphae similar to and continuous with 
those of the endoperidium, its external delimitation being 
due to gelification of the latter, the hyphae of the spore-sac 
remaining unchanged. The wall is about *5 mm. thick, 
yellowish white in colour, flexible, and perfectly free from 
the endoperidium except at the apex, where it remains 
attached to the inner surface of the teeth; but even here 
it is completely differentiated, and after soaking, by the 
exercise of a little care it can be entirely separated, when 
it resembles the mouth of the inner peridium in Geaster , 
the teeth being very delicate and continuous with an external 
circular depression in the substance of the spore-sac cor- 
responding to the portion in contact with a zone below the 
teeth of the endoperidium. The hyphse on passing into the 
spore-sac become thinner and are loosely felted, mostly 
aseptate, but a few sparsely septate branches occur. During 
the period of spore-formation the central mass or gleba is 
continuous with the inner wall of the spore-sac, and consists 
in an early stage of densely wefted trama-like bands enclosing 
irregular cavities as described by Fischer 1 in Sphaerobolus , 
but the development of this portion can only be satisfactorily 
studied in a complete series of living plants. The basidia 
are broadly obovate, measuring from 40-50 x 15-20 /x, and 
bear five or sometimes six spores supported on minute 
wart-like prominences arranged in a circle round the apex 
(Fig. 14 a). The spores are at first globose, smooth, and 
1 Zur Entwickel. der Gastromyceten ( Sphaeroboltis and Mitremyces ), in Bot. 
Zeitg. 1884. 
