New England coast, now under tidal influence, numerous 
stumps and roots may be recovered which retain to a 
great extent the color of the original wood, yet whose 
tissues are altered to a soft, almost cheese-like consist- 
ency. Similarly, the permanently submerged basal parts 
of wooden piles driven into sediments in both marine and 
fresh water environments show a peripheral zone of de- 
graded wood which may be relatively unchanged in color 
or gross appearance. Archeological remains of wood pre- 
served in the anaerobic environment of estuarine sedi- 
ments have been shown to undergo almost no ‘‘humifi- 
cation’’ or pronounced change from their original color 
(Bailey and Barghoorn, 1942). On the other hand, plant 
fragments from autochthonous peats or other organic 
accumulations in which aerobic degradation has played 
an important part almost invariably exhibit pronounced 
changes in color and the other physical and chemical 
modifications which feature the concept of ‘‘humifica- 
tion’’ (Waksman, 1938). 
However, all degraded plant tissues, whether ‘‘humi- 
fied” or visibly unaltered, are characterized by a signifi- 
cant reduction of their original cellulose, the extent of 
loss of cellulose being fundamentally an index of the de- 
gree of chemical and physical degradation. In view of 
these facts, which are well supported by numerous ana- 
tomical and chemical investigations (Mitchell and Ritter, 
1934; Jurasky, 1988; Cartwright and Findlay, 19438; 
Waksman, 1988; Jahn and Harlow, 1942; etc.), it is of 
interest to examine in detail the structural changes which 
occur during degradation of the cell wall. 
In order to orient the significance of these anatomical 
changes it is desirable to note briefly certain fundamental 
aspects of the structure of plant cell walls. Among higher 
plants the presence of a cell wall is the most conspicuous 
visible feature in the organization of tissues, organs and, 
[5] 
