DISEASES OF TAXODIUM AND LIBOCEDRUS. 75 
within the diseased centers and grows between these 
centers without affecting the intervening wood. This wood 
can be utilized for many purposes even when much rotted, 
and in neither case does the mycelium grow after the tree 
has once been cut down. The two trees thus diseased, 
both representatives of a race of trees the majority of 
which are extinct, are closely related genetically, although 
growing in different parts of the country. The two forms 
of decay differ but slightly, and not more than might be 
expected in two woods of different character. Taking those 
facts into consideration, it appears probable that the two 
diseases are caused by one and the same fungus, the fruiting 
form of which has not yet been found. 
EXPLANATION OF PLATES ILLUSTRATING DISEASES OF 
TAXODIUM AND LIBOCEDRUS. 
Plates 1, 2, plate 4, fig. 3, and the coloring of plate 3, 
fig. 2, and plate 4, fig. 2, were prepared under my direction 
by Miss Harriet P. Learned. 
Plate 1.—1, Branch of Taxodium distichum, showing early stage of 
the pecky disease. The wood turns yellow in longitudinal lines (<3). 
2, A block of Tazodium distichum cut from the heart of a tree several 
hundred years old, showing advanced stage of peckiness. In a large 
number of trees the rotted portion is more yellow than that shown in the 
figure (¢<1)- 
Plate 2. — A block of Libocedrus decurrens showing advanced stage of 
the pecky disease. The rotted wood has fallen out from the holes at the 
right of the figure leaving a smooth surface (<4). 
Plate 3. — 1, Transection of pecky cypress wood. The section was 
made so as to include some of the much rotted wood, seen at the bottom 
of the figure, also some of the sound wood. It was stained with phloro- 
glucin and HCl. The violet of the original section was somewhat more 
marked than is the color in the figure. The portions staining violet indi- 
cate wood which has not been affected by the fungus, those staining 
yellow show where the coniferin elements have been extracted: ‘m’ 
medullary rays; ‘k’ cell-walls from which the coniferin has been ex- 
tracted; ‘p’ normal cell-wall; ‘d’ primary lamella resisting the disinte- 
grating factor longer than the secondary lamellae; ‘h’ perforation of 
cell-wall made by fungus hypha (magnification same as fig. 2). 2, Tran- 
D3 
