The second tube should be bent to a right angle above the stopper and
its projecting end filed to a sharp point. Without removing the bag from
around the pistillate blossoms, the hybridizer forces the point of the
atomizer through the cotton wadding between bag and branch. The pollen
in the vial is blown through the tube into the bag in a cloud, covering
all the enclosed blossoms. It is advisable to repeat this on several
successive days to make certain of reaching the female blossoms during
their most receptive period.

[Illustration: _8 x 8 x 8 foot tightly woven sheet of unbleached muslin
stretched over mother hazel plant during pollination period in the
process of making controlled crosses between it and filbert parents.
Photo by C. Weschcke._]

[Illustration: THE WESCHCKE POLLEN GUN

Taper end of copper tube ... not absolutely necessary, but it saves
pollen.

Long fibre cotton wad wired to intake side of bulb to strain out foreign
pollens that may be in atmosphere.

De Vilbiss atomizer bulb.

Pollen grains

Any small glass bottle with a wide mouth and screw cap.

Tubes A and B--3/16" outside diameter copper tubing can be purchased at
any garage. Solder both tubes to screw cover C.

Drwg by Wm. Kuehn

_How to make pollen gun._]

Chapter 21

TOXICITY AMONG TREES AND PLANTS

Although quack grass will grow luxuriantly up to the trunks of both
black walnut and butternut trees, I know, from things I have seen
myself, that the roots of the latter and probably of the former have a
deadly effect on members of the evergreen family. I have seen northern
white pine and other pines, too, suddenly lose their needles and die
when, as large trees, they have been transplanted to the vicinity of
butternut trees. To save as many of these transplanted trees as
possible, it was necessary for me to sacrifice almost one hundred fine
butternut trees by cutting them off close to the ground and pruning all
the sprouts that started.

Other instances have also demonstrated to me this deleterious power of
butternut trees over evergreens. For years, I watched a struggle between
a small butternut tree and a large Mugho pine. Gradually the Mugho pine
was succumbing. At last, when the pine had lost over half its branches
on the side near the butternut, I decided to take an active part in the
fight. I cut off the trunk of the butternut and pruned off all of its
sprouts. The butternut surrendered and died. The Mugho pine