The Washington times., 1916-01-05
n q UGH OF the experimental work
NM in breeding stock and in

IVY raising crops Is based upon
verye important law of
heredity, which, for example. explains
the presence of color in flowers and In
the hides OF horses
Gregory Johann Mendel, the discov-
erer of this curious regulation OF her
edity. was a Bohemian monk and abb
bntt, who made experiments in 1855
which revolutionized5 biology,
MenjePs wonderful and now veri-
ned experiments remained unknown
until 1900, when an account of them
was unearthed In an obscure scientific
journal, Proceedings OF the National
History Society OF Brunn." At the
same time attention was called to FIR.
MendePB experiments by the great
bOtanists, De Vries, Tschermak, and
correus. Experimental workers had
not yet tackled the problems of her
edity, and "genetics.". as IL. is called,
was not even in mind.
Mendel took the common garden
pea for his experiments. This plant is
easily cultivated and produces several
generations In a year. IT has several
races. or pure lines" and also has
lite size and color. Greenhouse cul-
lures OF the garden pea yield three
generations, the different strains hav-
ing red. white or purple flowers. The
! seeds are wrinkled or smooth'and the
bushes are dwarfs or giants I'm size.
-. hVA ulCuUeA taW WOEkCOs
To investigate the lhwskof heredity,
not only must such distinctive an iso-
lated characters be Kept IN mind but
! the observations must be kept clear eX-
actly as to how much each parent con-
tributes to the offsprings' characters.
This holds for man, animal, Towering
plant or fungus. To avoid the difficulty
of parents with similar characters, a
hybrid is best for experimental pur-
poses. In this way the differences be-
| tween the parents are brought out in
sharp contrast in the progeny. When
Mendel crossed q purple-hOwered pea
| with peas that had white blossoms, the
ensuing generation at once emphatically
established the quota of each parents 3
/ contribution in colored flowers.
The mating of hybrids II to 'gene-
! ties" what the microscope is to other
sciences in that II makes facts so dra-
matically plain that those who wilfully
shut their eyes to the truth dare not
| deny 1t. Moreover. the laws Of heredity
| made thus evident apply with equal
that is to say. similar parents. Briefly,
what is discovered to be inherited in
one kind Of mating or crossing will be
found likewise true OF inheritance in
i general.
| The various races of garden peas
which Abbot Mendel selected were pos
| sessed OF so many characters and pos
sibilities that they might have confused
any Investigator less skillfuL He did
not divide his powers. however, but
gave strict heed through successive
generations to only one character at a
time. -r...s
First Mendel followed the color OF
flowers. Then their height or small
ness! was observed. To make the
classic tale short, what he found for
| one character also held for the others.
He brought to light the fact that II
makes no difference in inherited char
| acterlstics. whether they came from the
father or the mother.
Where Whiteness "GOes."
He used tho male purple flower to
cross with a white cne. and Vice versa.
| The progeny Of both matings were pur-
| pie This means that the purple factor
| in flowers dominates white in the next
generation. In genetics this is called
''hy brid generation" The essential
thing here is that despite the fact that
are purple. What has become OF the
| "whiteness?'
"Whitencss'' will bo discovered again
| in the grandchildren when ,he pur-
ple-fiowered plants are crossed will
each other. This proves that tie
| been suppressed or temporarily Ostra
| cized.
Most colors OF hair, eyes and fur in
| man and animals are dominant over
white. Grays are sometimes mixed. and
are not unit characters" in hercdity
as are \ legion of inherited char9cteris'
tics.
The law of heredity. however, tc
which this all applies, really appears in
the children Of the hYbrlds This gen.
Grafton of grandchildren Cf the first
pair has three kinds. In every foul