The Washington herald., 1913-06-01

est number Of distinct species and forms
of alfalfa ever brought together, 1t has
become manifest that until recently very
little was known about the life history
Of the alfalfas of the world. They are
q much mixed lot OF plants. and hardly
any Of them come invariably true to
seed-a fact evidently attributable to the
indiscriminate cross-pollination Of their
flowers by insects. But. as already
proved by the Plant Bureaus expert
ments. they can be bred to come true to
type.
The alfalfa flower resembles a sweet
pea blossom in miniature. 1t is very
tiny. and the sex organs are extremely
delicate and easily destroyed by the most
careful manipulation. For this reason
It has hitherto been found impracticabie
to cross-breed alfalfa. A method often
tried has been to sthrust a sharpened
splint Of wood, previously busted with
the desired pollen. into the ''keeP' Of
the flower meant to serve as seed
bearer-the splint being intended to imi-
tate the proboscis of a bee. But ex-
periments of this kind have not been
attended with success. and breeders have
been driven to fall back upon the crude
expedient Of setting out few plants
of q known variety Ito serve as seed
bearers In the midst Of a field of an
other variety-trusting to the happy ac-
cident of pollination by insects.
The problem. however, has been solved
by Mr.. divers recent discovery Of an
easy means whereby. with a little prac-
tice. anybody can mate varieties of
alfalfa. In place Of surgical Instruments
a hne jet of water is employed. and the
only apparatus required Is a rubber
water-bulb of the sort commonly used
by dentists.
II one examines an alfalfa flower. one
finds that 1t is composed of banner.
two wings ION either side of the ban
ner). and a keel" opposite the banner
1t is the keel that contains the repro
ductive parts of the blossom. When
humble bee comes along, and thrusts
her proboscis into the keel. out jumps
a little greenish rod strikes violently up
on her thorax, and scatters pollen grains
Presently she flies away. alights upon
another flower. and incidentally fertiIizes
the latter with the pollen she brings
from the first blossom In this way
mating is accomplished.
but the proboscis of bee Is an instru-
ment Infinitely more delicate than any
that can be made or used by man. I does
the work without injuring the sex or
gans of the flower. The water-jet, how
ever, is equally effective. and, when SCI
entifically employed, replaces accident
with certainty, the two blossoms to be
used as PARENTS. e., as pollen-bearer
and seed-bearer. respectively - being
chosen for the purpose beforehand
To begin with, a flower Is selected that
Is to serve as the mother" or seed
bearer. A pin Is thrust crosswise be-
tween the banner and the keel. and then
slight snip with a pair of delicate
forceps applied to the keel causes the
little rod to jump out. This Is called
tripping the flower. II the pin were
not previously placed in position in the
manner described. the rod would strike
with force against the banner and scatter
its pollen; but the pin prevents this, hold
ing the rod back and in position while
ths operator directs upon it a fine jet of
water from the. rubber bulb-the force of
the jet being regulated to a nicely by
the pressure Of the hand that grasps It.
A few seconds suffice to remove all the
pollen grains from the rod. II the latter
be then examined with q magnifying
glass, small green spot will be seen in
the middle of its end. This is the stigma
(the female organ Of the hower) which