~ cent and show the bun- 
FLAX-STEM ANATOMY IN RELATION TO RETTING. Et 
surfaces and concave and grooved on the surfaces that face toward 
the center of the stem. From the standpoint of retting the degree 
of concavity is of interest, as the deep grooves furnish natural 
places for the separation of the fiber bundles during the retting 
process as well as during the subsequent processes of breaking and 
scutching. Frequently there is anastomosis of several fiber. bun- 
dles coming up from the base of the stem, so as to form one large 
bundle, and it is quite common to find deep indentations marking 
the spots where union took place. These grooves make it easier for 
the large bundles to be retted and separated into smaller units. The 
irregular shapes and sizes of the fiber bundles help to explain the 
difficulty of obtaining a uniform ret and also explain why linen 
threads and cloth do 
not have the same uni- 
formity as cotton of 
the same quality, since 
all cotton fibers are 
single cells of uniform 
diameter. 
Figures 4 to 8, in- 
clusive, show a series 
of external longitudi- 
nal views of the cortex 
and fiber during the 
last stages in retting. 
In Figure 4 retting has 
separated the cortex 
from the wooden core, 
but the cortex is still 
almost intact and un- 
divided. The leaf scars 
have become translu- 
Fic. 6.—Changes in the appearance of the cortex of 
dle traces. In Figure flax dupZig = last freee of petting: Only a few 
: pieces of epidermis and parenchyma here remain 
5 the cortex has sepa- clinging to the fiber pane which are not yet sepa- 
4 1 2 - rated into the small widths necessary for industrial 
rated into a number of eee ee CAO. 
smaller strips, the bac- | 
teria have destroyed most of the parenchyma and epidermis that held 
the fiber bundles together, but the epidermis and parenchyma are still 
clinging to the bundles in fairly large pieces. In Figure 6 only very 
small pieces of epidermis and parenchyma are found clinging to the 
fiber bundles, but the leaf scars persist, and the fiber bundles are not 
yet separated into the small widths of fiber necessary for industrial 
use in spinning. In Figure 7 retting is completed, the leaf scars have 
disappeared, the fiber bundles are entirely tree from impurities, and 
are split lengthwise into fibers of suitable widths. The fibers in 
Figure 7 may be compared with those in Figure 8, in which a repre- 
sentative sample of uncombed water-retted Dutch fiber is shown. 
The microscopical study carried along with the retting process 
confirms the work of other students of retting in that the outside of 
