FLAX-STEM ANATOMY IN RELATION TO RETTING. Dt 
core out toward the root end of the stem, and test 7, in which the 
leaf-scar test is made by peeling the girth of cortex away from the 
wooden core at right angles and toward the panicle end of the stem. 
For best results with test 7 the hand holding the stem is moved along 
directly behind the place where the peeling takes place, and the stem 
is held horizontally. These two tests are hereafter designated, respec- 
tively, as the loose-core and the leaf-scar tests proper. They were 
compared with considerable accuracy, as the same stems were used 
oe 
TI'ic. 16.—Step 3 in the loose-core test of retting flax fibers. One hand holds the stem 
above the second break in the wooden core, while the other exerts a pull on the ex- 
posed lower end. 
: 
in making both tests. At each interval when observations were made 
10 stems were withdrawn one at a time and the tests alternated, 
using the root-end half of the first stem for the loose-core test and 
the panicle-end half for the leaf-scar test and then reversing the two 
Fic. 17.—Step 4 in the loose-core test of retting flax fibers. Retting is said to be com- 
plete if the wooden core slips easily out from the cortex without any of the fibers 
clinging to it. 
portions used for the next stem. In this way 10 tests were made 
with each method of testing and in each case 5 root-end and 5 panicle- 
end halves were used from the same 10 stems. The resistance to 
separation was lost with the loose-core test long before the completion 
of retting, but the resistance to separation was retained in the leaf- 
scar test until retting was practically completed. At the time when 
the loose-core test gave positive indication that retting was com- 
pleted, through the loss of resistance to separation of the cortex and 
