[VoL. 3 
18 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
Just below the spore crust, especially towards the center, the 
typical cinnamon-buff strands of the Ozoniwm occurred in 
abundance. A similar type of mycelium also permeated the 
soil to a considerable extent in the immediate vicinity and often 
about the periphery of the spore-bearing area. 
The study of the collections made in 1915 emphasize the 
diversity in the form of hyphae as well as in the method of 
spore production. Although no circular areas were found in 
an early stage of development, yet some of the older ones 
yielded on the periphery material from which the method of 
spore formation could be followed. It would appear that a 
superficial growth of large, branched, almost hyaline hyphae 
is first formed (fig. 2), covering the surface with a delicate 
stratum. These hyphae are sometimes Rhizoctonia-like. 
They may also bear conidiophores at irregular intervals, the 
latter arising usually as short assurgent branches. These 
branches either produce conidia directly, or commonly after 
becoming variously forked (fig. 1). As further growth pro- 
ceeds, however, definite strands are developed, and then 
swollen branches from any cell of the strand may produce 
spores. Later the wave of spore production appears to in- 
volve practically the whole mycelium, and the conidia are 
found laterally distributed in various positions on the surfaces 
of both the strand and simple hyphae, so that in the end there 
is practically nothing left but a pulverulent mass consisting 
of the conidia and remains of the mycelium and strands. The 
conidia are sessile, but occasionally cells bearing conidia ex- 
hibit a somewhat roughened surface. The true character of 
the fungus cannot be determined unless one is careful to se- 
cure the youngest material available, that is, from near the 
margin of the spore area, or otherwise a spore-forming area 
in an early stage of development. 
The diverse characteristics of the mycelium, as found on 
the surface of the host and in the soil, may be briefly sum- 
marized as follows: 
(1) Large-celled type. Hyphae Rhizoctonia-like, often 
abundant on the margins of the conidial areas, measuring 
frequently 20и in diameter, with cross walls 60-120» apart. 
This type should also include some of the arachnoid mycelium 
