Nov., 1922] KAUFFMAN AND KERBER HEART-ROT OF LOCUST 
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in order to compare the cellulose and lignin tests in a positive way, micro- 
tome sections were made of wood from a sound tree from another source, 
cut in the three planes : cross, radial, and tangential. There was, of course, 
quite an elaborate technique involved in merely trying to find the dif- 
ferentiation of cellulose and lignin tissue in black locust, but the time was 
well spent as will be shown later. Permanent slides were attempted for 
the diseased portion of the wood of the tree studied but without success, 
because of the damaging influence of the hydrofluoric acid on the already 
weakened tissues. 
All sections were taken from sound wood of section I and from one to 
two inches in from the sapwood. Sections were radial and tangential ones. 
These tests were corroborated by permanent mounts of black locust stained 
with haematoxylin and safranin. 
Table i . The Result of Staining for Cellulose and Lignin in the Normal Wood 
Elements 
Med. ray cells. . . 
Tracheids and vessels 
Cellulose Test 
Good cellulose test, deep blue 
color; not all ray cells 
showed cellulose test 
Did not show any cellulose 
reactions, with the excep- 
tion of the tyloses in the 
vessels, which are pure 
cellulose 
Lignin Test 
Some ray cells showed good 
lignin color (True of ray 
cells in heartwood of 
black locust) 
Showed a good lignin test, 
with exception of tyloses 
Wood parenchyma, 
These showed a good cellulose 
blue reaction, in decided 
contrast to the vessels 
which they surround 
Did not show a lignin test 
Wood fibers. 
, These showed both a cellulose 
and lignin reaction, due 
to two types of fibers pres- 
ent in locust: mucilagi- 
nous fibers which stain blue 
with haematoxylin, and the 
ordinary fiber which stains 
red 
Showed a good lignin stain 
for the ordinary wood 
fiber present in black 
locust 
In testing the decayed portion of section I, sections were taken of 
(a) the black border zone; {h) the less decayed portion of the wood; and 
(c) the badly decayed portion of the wood. Radial and tangential sections 
were made of all these parts. 
