76 MISSOURI BOTANICAL GARDEN. 
section of pecky cypress wood, showing the transition from sound wood 
to humus compound, after staining with phloroglucin and HCL: ‘g’ 
primary lamella, unaffected; ‘p’ small masses of humus compound 
resulting apparently from the transformation of the tertiary lamella; ‘i’ 
wood staining yellow, an intermediate stage between the sound wood and 
the humus compound; ‘h’ a thicker layer of humus compound than 
the one indicated at ‘p’;‘c’ a still more advanced stage in the humus 
formation; ‘e’ the entire cell-wall has been transformed into the 
humus compound; ‘u’ piece of cell-wall not yet changed to humus 
compound, 
Plate 4.—1, Transection of sound wood of Libocedrus decurrens, 
showing spring and summer wood: ‘h’ brown hypha with attachment 
organs; ‘s’ spores often found in the wood cells. 2, Transection of 
diseased wood of Libocedrus decurrens, i.e. wood from one of the pockets. 
The color is the natural color of the wood. The medullary ray is filled 
with brown humus solution. 38, Block of Taxodium distichum showing 
pecky hole lined with white fibers, consisting of pure cellulose (<4). 4, 
Two tracheids from wood surrounding a diseased spot in Taxodium 
distichum. The tracheids are filled with brown humus compound which 
has cracked in drying. 
Plate 5.—1, Mycelium from decayed wood of Taxodium distichum, 
showing the numerous clamp connections. 2, Spores from pecky wood 
of Libocedrus decurrens. (The line at the topis10.) 8, Portion of a 
tracheid near diseased area of Taxodium distichum. The pits appear 
corroded because of a peculiar arrangement of resin globules. (Magni- 
fication same as fig. 2.) 4, Brown chlamydospores from rotted wood 
of Taxodium distichum. 5, Brown spores from wood of Tazodium dis- 
tichum. These are like the ones found in the redcedar. 6, Spores from 
wood of Quercus alba destroyed by Polyporus sulphureus (from Will- 
iamsville, Mo.; magnification same as fig 5). 7, Spores from wood of 
Taxodium distichum, resembling Willkomm’s Xenodochus ligniperda. 8, 
Minute bodies, which appear in the humus compound when the latter is 
slowly dissolved away. ‘Two views are represented (magnification same 
as fig. 2). 9, Mycelium showing attachment organs: ‘a-c’ from wood 
of Taxodium distichum; ‘d-f’ from wood of Libocedrus decurrens. 10, 
Longisection of pecky cypress wood, showing gradual disintegration of 
the tracheids: ‘a’ normal tracheid filled with humus compound; ‘b’ 
similar tracheid with colorless mycelium; ‘c’ tracheid with pits looking 
as if corroded; ‘d’ tracheids with walls which are beginning to contract; 
‘e? tracheid in which the walls show spiral cracks; ‘f’ and ‘ g’ tracheids 
showing final stages in the process of solution. (Magnification same 
as fig.1.) 11, Longitudinal section through pecky wood of Libocedrus 
decurrens: ‘a’ normal tracheid; ‘b’ tracheid showing beginning of 
disintegration, the pits show cracks, some spores are collected near 
a wall; ‘c’ and ‘d’ tracheids which have contracted considerably, show- 
ing cracks in the pits and the wall. (Magnification the same as the pre- 
ceding figure.) 
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