The Washington times., 1933-10-21

Secrets Of
Health
By DIR. LOUIS e. BISCH
The Term Hereditary" Has .
Distinct Meaning

The Term Hereditary" Has .
Distinct Meaning
The term Heredity is used
very loosely by the average per-
son. In fact, it is often used as
an excuse-a sort of "alibi,"
one might say. Thus one often
hears it said that So-and-So is
suffering from this or that dis
ease because he or she inner
tied it. In point of fact, few
disorders, of whatever kind, are
actually known to be hereditary.
When scientists speak of
heredity they naturally think
of that famous monk named
Gregor Mendel, after whom the
Mendelian Hypothesis Of Hered-
ity is named.
MendeI Theory
Mendel had been experiment
ing with the croSs-fertilization
of ordinary garden peas for
eight years before he came to
his revolutionary conclusions
and published a paper about
them. This paper appeared in
1865 in the proceedings Of the
Natural History Society Of
Brunn."
Perhaps the most remarkable
thing about this paper is the
fact that, although it was des-
tined to change markedly the
then existing thought on hered-
ity and to become a monu-
mental contribution in its
field, the marvellous deductions
remained practically unknown
and neglected for thirty-five
years! Mendel's discovery
that is, the laws of heredity
which he formulated after
studying how peas may be
made to change in successive
generations-did not receive
scientific recognition until a
few years after Darwin had
published his "Origin of the
Species"
Specifically. what Mendel
did was to plant two varieties
of peas one tall and the other
dwarf. Then, by transferring
pollen from one to the other,
or by cutting out the stamens,
he was able to grow all tall
plants and later a definite
number of tall plants to every
dwarf.
Traits
These experiments we're, Of
course, highly complicated and
the explanation of them is
even more so. Suffice it to
say that the terms dominant"
and "receSSive," which one
meets with so often in reference
to traits and physical weakness
in heredity studies, came into
being in this way
AS stated previously, science
knows of but few conditions
that are hereditary. The color
Of the eyes is one of these. The
disease known as Hemophilia
-popularly called "Bleeder's
disease-is another.
The cause of feeble-minded-
ness is open to doubt although
many arguments may be ad-
vanced to prove it is hereditary.
The same may be said Of cpl
lepsy. But such disorders as
insanity, alcoholism, tubercu-
losis, and the like-diseases, in
other words, which are usually
considered hereditary-have not
been shown to follow the Men
delian laws.
Tendencies
Whether, if a certain disease
tuberculosis, let us say, in one
or both parents) exists in the
family, there is a distinct
tendency for its development in
the offspring rather than an
hereditary transmission, is also
open to question. Some scien-
lists believe that a tendency, if
not the disease itself, may be
inherited.
At any rat. we must never
become alarmed when we learn
that some member of our fam
lily has suffered rom a de-
vastin- disorder. The chances
are that j. is not hereditary
anyway. And if a tendency to
such a disease may be inher-
tied, then all we have to do is
be spec llv careful in our hy-
gien- Of living.
Such warning is, at least,
a tremendously valuable safe