[VoL. 3 
472 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
edge of the celluloses. A full review of the chemistry of cellu- 
lose is given by Schwalbe (’11) in a very comprehensive way. 
It suffices to say here that the decomposition products of cellu- 
lose are mono- and disaccharides, and the decomposition may 
be brought about more or less readily, according to the com- 
plexity of the cellulose molecules, by the action of acids or 
alkalis and by the hydrolysis due to enzyme action. 
An adequate review of the literature concerning the róle 
of microorganisms and filamentous fungi in the fermentation 
of cellulose, especially in the soil, may be had by recourse to 
the papers by Kellerman and McBeth (’12) and McBeth and 
Seales (713). Much of the literature on early experiments 
with parasitic fungi and their ability to pierce the cell mem- 
brane is reviewed in the above-mentioned papers, as well as 
by Cooley ('14). Space will permit only a brief review of 
some of the more important later papers dealing more closely 
with the destruction of the true cellulose of wood fibre after it 
is set free from the lignocellulose. 
Czapek (799*) found in the decay produced by Merulius 
lacrymans that the cellulose disappeared from the cell walls, 
and he concluded a priori that a cellulose-hydrolyzing enzyme 
was excreted by the fungus, although he was unable to demon- 
strate it experimentally. Ward ('97) observed that in the 
progress of wood destruction due to Stereum hirsutum 
the action proceeds from the lumen outward. The sound 
wood (Aesculus) gives no cellulose test, but the first signs of 
dissolution are the swelling of the layers next to the lumen 
and the separation of the lumen from the layers next to the 
middle lamellae. These swollen layers give the test for cellu- 
lose, and as they disappear the next layer becomes delignified, 
gives the cellulose test, and finally disappears. The middle 
lamellae remain untouched. Ward did not attempt to isolate 
the enzyme which hydrolyzed the cellulose. According to 
Buller (’05), wood is rotted by Lentinus lepideus in much the 
same manner as by Merulius and Stereum. It shrinks and 
cracks on drying, and is then very brittle and friable. The 
free cellulose is removed by the fungus. 
