1917] 
ZELLER— DURABILITY OF YELLOW PINE 105 
STERILIZATION 
The jars were sterilized in an autoclave for 45 minutes at 
20 pounds pressure. Tests were conducted on sterilizing the 
cultures when they contained sufficient water for inoculation 
and when no water was added. It was found that some of 
those sterilized in a wet condition lost resin by steam distil- 
lation, and that the resin was not lost by sterilization if the 
blocks were dry and placed in a dry jar, although sterilized 
in steam in an autoclave. The loss of resin proved to occur 
when the blocks contained more than 17.6 per cent resin. 
There is a criticism, however, of any method of sterilization 
by heat when wood containing resin is concerned. Heat will 
necessarily rearrange the resin from the condition in which 
it naturally exists in wood. This is probably the greatest 
error in the present preliminary work along this line of inves- 
tigation. 
Tests on the effect of sterilization on the lignin elements 
were conducted. It was found that thin shavings of wood in 
water autoclaved for one hour were not delignified to such 
extent that by staining with zinc chloriodid any change could 
be detected, although the water in which the shavings had 
been boiled gave a very faint pink color with phloroglucin 
and hydrochloric acid. Potter (’04) believed that any method 
of sterilizing with heat considerably altered the lignin of 
wood. His tests were made on very young wood, however. 
Spaulding (’06) repeated Potter’s tests and found that it 
takes 15 to 40 hours of sterilizing at 100° C. to effect any 
change in the wood elements. 
INOCULATION 
After the jars were sterilized the cultures were moistened 
by adding sterile distilled water, and then were inoculated 
with Lenzites saepiaria. In a previous paper methods of ob- 
taining pure cultures and the propagation of the fungus on 
various media — Thaxter’s potato-hard agar, pine sawdust, 
and blocks of pine wood — have been described in detail. Agar 
was found to be the best medium to employ in growing the 
fungus to be transferred to these block cultures. The fungus 
