1916] 
ZELLER—PHYSIOLOGY OF LENZITES SAEPIARIA 445 
Increase in sporophore-producing capacity.—The basidio- 
spores from one of the sporophores produced in pure cultures 
were caught in a sterile Petri dish and plated out in agar as 
described above. There was a large per cent of germination. 
The pure culture tubes made from these germinated spores 
produced sporophores on agar in eight weeks after the trans- 
fers were made. This is the only instance where I secured 
sporophores of Leneites saepiaria on agar. It seems plausible 
to conclude that by growing the fungus in pure cultures the 
ability to produce sporophores in cultures is increased in the 
following generation. 
FACTORS INFLUENCING THE GROWTH AND METABOLISM OF 
THE FU 
In this connection four different factors are discussed. 
These are (1) the relation to the reaction of media, (2) tem- 
perature relations, (3) the water and oxygen content of the 
substrate, and (4) resin on wounds and in the wood. 
(1) The relation to the reaction of media, with special 
reference to chemical composition, i. e., source of carbon and 
other nutrients for best germination and growth, has been 
amply considered by Rumbold (’08), and by Falck (209) in 
his monograph on the Lenzites rots. Thus it was not con- 
sidered necessary to dwell upon these factors further than is 
reported elsewhere in this paper. However, in making a new 
supply of cultures of Lenzites saepiaria, Fomes pinicola, 
Polystictus hirsutus, Polyporus lucidus and others, I found 
that after transferring to the new medium the fungi would 
not grow. On testing with litmus this medium proved to be 
slightly alkaline. A readjustment of the reaction to slight 
acidity yielded a suitable medium for these forms. Rumbold 
(208) also found that L. saepiaria is very sensitive to alkaline 
media, and Spaulding (711, p. 19) found that “а number of 
experiments uniformly gave the same results with this 
species. It was found that even with one-fourth of one per 
cent of sulphuric acid it grew luxuriantly.’’ 
(2) In Falck’s (209) paper temperature relations are dis- 
cussed at length. He shows that L. saepiaria has a growth 
