133 
Xylem of Woody Stems . 
The inoculation of the gelatine tubes from the cold-water extract 
of the Oak duramen and alburnum and the subsequent development of 
colonies clearly showed that Bacteria were present in these solutions, but 
further proof was needed to show whether or no these Bacteria could live 
upon and destroy the substance extracted from the wood by water. To 
determine this point strong decoctions were made from splinters of the 
duramen and alburnum of the same forty years’ old stem. The splinters 
were boiled in water in two flasks, and after standing all night in the 
steamer were again boiled on the following morning. The decoctions 
thus obtained were freed by filtration from any particles of wood and 
drawn into smaller flasks, each containing 150 c.c. of decoction. In 
this manner eight flasks were prepared, four containing each 1 50 c.c. of 
alburnum decoction and four containing each 150 c.c. of duramen decoction. 
These will be referred to as alburnum- and duramen-* decoctions.’ These 
eight flasks were then plugged with cotton wool and sterilized by dis- 
continuous steaming. Of the eight flasks one of each kind was used 
for a control. 
Of the other three flasks of alburnum-decoction one was sown with 
Penicillium , another with Bacillus subtilis — a pure culture obtained from 
Dr. Krai — and the third from the alburnum-extract in which the Bacteria 
had developed. Similarly one flask of duramen-decoction was sown with 
Penicillium , a second with B. subtilis , and the third from the duramen- 
extract in which Bacteria had developed. These flasks together with 
the controls were incubated at 28° C. 
Flasks sown with B. subtilis. After twenty days stab-cultures were 
made on gelatine-tubes of Koch’s beef-bouillon and Liebig-extract, and 
the flasks were then extracted with ether and tested as before. With 
phloroglucin the duramen-residue gave a most distinct red, but the colour 
was much fainter in the alburnum-residue. With thallin sulphate the 
colour was indicated in both cases but more faintly in the alburnum- 
residue, and with phenol-HCl no reaction could be detected in either case. 
In the stab-cultures, colonies developed from the alburnum-decoction, 
but not from the duramen. This experiment seems to indicate that 
B. subtilis can grow in the alburnum-decoction and destroy the substance 
extracted from the wood, while it is incapable of living in that obtained 
from the duramen. 
Flasks sown from alburnum - and duramen-extracts. After twenty- 
one days stab-cultures were made from both flasks in tubes of beef-bouillon 
and Liebig-extract. The stabs from the alburnum-decoction developed 
colonies which quickly liquefied the gelatine, but the colonies from the 
duramen-decoction developed much more slowly and without liquefying 
the gelatine. The ether-extracts from the alburnum-decoction showed no 
colour with either phloroglucin or thallin sulphate, but in the case of the 
