Dec. io. 1917 
Flaxwilt 
589 
METHODS USED IN CROSSING AND SEEPING PEANTS 
After thoroughly testing the different strains of flax on “sick soil” 
and selecting the most suitable ones for the work, crosses were made 
between plants of the resistant and susceptible strains. The first crosses 
were made with plants grown in the greenhouse on soil free from F. Uni. 
These crosses were fairly successful. In the summer of 1915, plants 
were grown in the field, and a large number of crosses were made between 
the different strains in a manner to be described later. These crosses 
were more successful than those made in the greenhouse. The best 
results were obtained from crosses made with the first few buds to appear 
on the plant. This is no doubt due to the fact that the plant is at its 
maximum sap content and highest state of activity at this stage and is 
more able to overcome any injury that might be done to the flower 
through the operation. After the plant becomes more mature, a lower 
percentage of the artificially pollinated flowers develops. The operation 
should be performed at about the time when the petals begin to show in 
the bud. At this stage the authers are not fully mature and are not 
so easily broken open. The petals can be removed very easily by catch¬ 
ing the tip of the bud with a small pair of forceps and pulling gently. 
Care should be taken not to catch too low on the bud, or the stigma 
may be broken or injured. Eyre and Smith ( 13) state that they removed 
the petals by a sudden jerk, removing the stamens at the same time. 
The writer was not able to do this with the varieties of flax used in this 
work, without injuring the stigma. 
After removing the petals the sepals can be pushed aside and the 
anthers removed by carefully pinching off the filaments with forceps, 
which should be sterilized by dipping them in 50 per cent alcohol before 
and after each operation to avoid contamination. After this operation 
the flowers are ready for pollination. Flowers pollinated a day after 
emasculation gave no better results than those pollinated immediately 
after the process. Pollination is easily accomplished by taking a flower 
which has just opened from the plant to be used as the male parent 
and brushing the anthers directly over the stigma of the emasculated 
flower. It is very easy to tell when the anthers are open by the mealy 
appearance of the pollen on the surface. Before opening they are smooth 
and white. After the flower has been pollinated it should be covered 
to keep out insects and other agents of contamination. Small glacine 
bags and waxed paper rolled on a fountain pen and tied at the ends 
were found to be quite satisfactory for protecting the flowers. After 
the capsules begin to develop it is better to remove the covering, espe¬ 
cially in the greenhouse, where there seems to be a smothering of parts 
covered in this way. In the field, where the rolled paper was used, the 
seed developed in good condition even though the paper was not re¬ 
moved. The bags, being tighter than the rolled paper, prevented aera- 
