1916] 
ZELLER— PHYSIOLOGY OF LENZITES SAEPIARIA 443 
CHARACTERISTICS OF THE MYCELIUM IN CULTURE 
Lenzites saepiaria was kept in cultures on three types of 
media, ie. Thaxter’s glucose-potato-hard agar described 
above, yellow pine sawdust in Erlenmeyer flasks, and pine 
blocks in jars and bottles. The mycelial characters on wood 
are somewhat different from those on agar. 
Polymorphism.—Polymorphism in the Basidiomycetes has 
been reported by many early investigators, and in late years 
especially by Falck in 1902 and Lyman in 1907. Lyman 
reviews the literature dealing with the occurrence of oidia, 
chlamydospores, and conidia in certain Polyporaceae, and in 
his own work finds that many of the Hymenomycetes possess 
these several ways of reproducing vegetatively. In 1909 
Falck published a monograph on Lenzites in which he de- 
scribes minutely the morphology and physiology of the myce- 
lium of L. saepiaria. The polymorphism of this fungus is 
extremely interesting and characteristic, the pure cultures of 
the mycelium being almost sufficient to identify the fungus. 
The mycelium is white at first, but with age the aérial part 
becomes a reddish brown or sepia color. When the mycelium 
grows out from an inoculum on agar, there is a submersed 
mycelium which is a forerunner of the superficial. From the 
latter there arises a woven mat of aérial hyphae which take 
on the sepia color with age. The hyphae are very much sep- 
tate, and clamp connections are quite common. These vary 
from the ordinary clamp connections through all stages to the 
medallion mycelium, as Falck calls it, which is found only in 
the wood and sawdust cultures. 
Falck divides the oidia into primary, secondary, and ter- 
tiary. The primary oidia are those formed when the whole 
superficial mycelium breaks up into chains of spore-like cells. 
The secondary are those produced at the tips of branches of 
the superficial mycelium. These may be abnormally swollen 
tips or very short chains from lateral branches. The ter- 
tiary oidia are the most common and appear on the aérial 
hyphae. The hyphae generally break at clamp connections to 
produce this type. The chlamydospores or gemmae are noth- 
ing more than swollen vegetative cells of the hyphae, which 
