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466 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
Ligninase.—It has often been sought to determine compre- 
hensively the chemical composition of the non-cellulose com- 
ponent of woody membranes. Tiemann and Haarmann, in 
1874 (cited from Grafe, '04), believed this component to be 
coniferin, while Singer (’82) considered lignin as a mixture 
of coniferin, vanillin, and wood gum, which gave a test for the 
aromatic aldehydes. The prompt action of Schiff’s aldehyde 
reagent with rose aniline and sulphurous acid speaks for the 
occurrence of aldehyde-like substances in lignin. In fact, in 
1898, Czapek succeeded in splitting off a substance from 
lignin by cooking it in stannous chloride solution. This sub- 
stance gave the typical wood reaction when treated with 
phloroglucin and hydrochloric acid, and was described by him 
as an aromatic aldehyde which he called hadromal. Accord- 
ing to Grafe (704), Czapek’s hadromal does not act like a 
homogeneous body but like a mixture of vanillin, methyl fur- 
furol, catechol, and coniferin, which substances exist in the 
form of an ether-like compound with the cellulose of the cell 
wall, or are taken up by resin, or may be found free in slight 
amounts in the wood fibre. According to Czapek (713), how- 
ever, catechol and vanillin may be regarded as decomposition 
products of hadromal. 
Other authors go only so far as to state that the substances 
making up lignin are intimately related to colloidal sub- 
stances, and can exist neither as a chemical compound with 
cellulose nor as its transformed product. On the other hand, 
Cross and Bevan (’01) hold that lignocellulose (lignin) is a 
complex of normal cellulose with two bodies, the one a fur- 
furol-yielding group, the other an aromatic or benzenoid 
group. Thus the chemistry of the lignocelluloses is such an 
open question that the decomposition products produced by 
enzymes from fungi are still worthy of attention. 
Our knowledge of the decay of wood induced by fungi prac- 
tically began with the fundamental researches of Hartig (’78) 
who has furnished extensive data concerning the parasitic 
and saprophytic fungi destroying the most important species 
of wood. He has shown that a radical change in the lignified 
walls is wrought by the fungus, and that in the first stages of 
