FLAX-STEM ANATOMY IN RELATION TO RETTING. 3 
and comes through the machine uninjured. In scutching, the fiber, 
which has been run through the brake, is evened up and exposed 
to the blows of a paddle wheel which beat off any shives that remain 
clinging to the fiber. If the fiber is much overretted, it will be 
weak and go to pieces as it passes through the brake. If it is under- 
retted, the shives will cling persistently to the fiber, and much 
long fiber will be wasted in the scutching process before the shives 
ean be beaten off. 
The factors that interfere with the retting objective may be 
divided into those of variable straw quality and those due to variable 
retting conditions. The freedom from shives, and the luster, the 
color, and the softness of the fiber are almost entirely determined 
by the management or mismanagement of the retting process, but 
nearly all the other characters on which flax fiber is graded may be 
influenced by the straw qualty, which is, in turn, influenced by the 
manner in which the crop is cared for, as well as by the kind of seed 
used, the quality of the soil, and the season or climate. 
STEM FACTORS AFFECTING RETTING. 
Strength of fiber may be influenced by the variety of seed used or 
by the soil. Different varieties of fiber flax differ considerably in 
the strength of fiber. Stems of White Blossom Dutch have less fiber 
strength than stems of Blue Blossom Dutch of equal diameter, and 
the fiber in the stems of Saginaw, a variety selected for superior 
stem length and strength of fiber, has greater strength than that in 
either of the preceding varieties. Flax stems produce weaker fiber 
when grown in*marshy or sandy soils? than when grown in clay- 
loam soil. The strength of fiber may be influenced also by season or 
climate; a dry climate or season produces fiber that is relatively 
weak. 
The fineness of fiber is influenced both by heredity, as represented 
by differences in the varieties of seed used, and by environment, as 
represented by the growing conditions. The fiber of White Blos- 
som Dutch is coarser than that of Blue Blossom Dutch, due to 
hereditary differences.’ According to hand-lens examinations of fiber 
from the 1922 crop at East Lansing, Mich., the fiber of White Blos- 
som Dutch is coarser than that of Blue Blossom Dutch, even wher 
stems of equal diameter are compared. The thickness of the stand 
of flax as controlled by the rate of seeding or by injuries from frost 
or disease determines the size and the uniformity of the stem diam- 
eter. A thick stand that has not been injured by frost or disease 
causes crowding of the flax plants and produces stems of fine diam- 
eter. Stems of fine diameter in turn produce fine fiber. Figure 1 
shows at the left unretted fibers taken from a stem of Blue Blossom 
Dutch 1.3 millimeters in diameter. Compare the fine quality of this 
fiber with the relatively coarse fiber shown at the right from a stem 
1 Davis, Robert L. Pedigreed fiber flax. U.S. Dept. Agr. Bul. 1092, p. 18. 1922. 
lpoyier Gustaf. Inhemska fibervixter. Jn K. Landtbr. Akad. Handl. och Tidskr., 
arg. 60, p. 388-424, 13 fig. 1921. (Manuscript translation by Ebba Oleson Campbell, 
p10. "On file in the Office of Fiber Investigations, Bureau of Plant Industry.) 
*Tammes, Tine. Die blau-bliimigen und weiss-bliimigen Flachsarten und ihre Bedeu- 
tung. In Forsch.-Inst. Sorau Verbandes Deut. Leinen-Industrieler Mitt., Jahrg. 2, Nr. 
6-7. 1920? (Manuscript translation by Lucile Reinbach, p. 9. On file in the Office of 
Fiber Investigations, Bureau of Plant Industry.) 
