PEDIGREED FIBER FLAX. 
17 
Plant-breeder's calipers. — For measuring diameters of small plant 
stems the plant-breeder's calipers (Fig. 7) have been found a 
source of convenience with flax. The stem to be measured is inserted 
in the notch N. The scale magnifies the stem diameter 20 times, be- 
cause it is 20 times as 
far as the stem notch 
from the place where 
the pointer is pivoted. 
Plant-breeder's 
envelope. — These en- 
velopes (Fig. 8) are 
made on a sewing ma- 
chine by stitching to- 
gether two sheets of 
oiled paper. An un- 
stitched portion is 
left at the base. This 
is slit up the middle, 
and at the apex of 
the slit a hole is cut 
to fit the stem of the 
emasculated flower. 
After the stem has 
been inserted in the 
envelope the un- 
stitched part at one 
side of the slit is 
folded at right angles 
and that on the other 
side at an angle of 
45° to the base of the 
envelope. At the 
point where these 
folded parts overlap 
they are fastened 
with an ordinary 
dress snap fastener. 
These envelopes can not come unglued, and they have the additional 
advantages of being light in weight and moisture proof. 
COMMERCIAL TEST OF PEDIGREED FIBER-FLAX STRAINS. 
Whether the improvement be secured through cross-pollination 
or by straight selection, it is necessary that the results obtained in 
the experimental plats be tested on a commercial scale in order to be 
Fig. 7. — Plant-breeder's calipers. 
