The midland journal. (Rising Sun, Md.) 1885-1947, 1919-05-02
LAWS OF HEREDITY
Vital Facts Which Are Not Prop
erly Understood.
Physical Development, More Especially
Among the Lower Animals, Largely
Matter Of Environment
In Human Family.

The laws Of heredity are not well
understood. There are many facts
pertaining to heredity which are well
known, but there are so many excep-
lions to the rules, nothing in the way
Of positive laws can be stated. Ac-
cordlng to the supposed laws Of hered-
ity there should he no difference what
ever In the physical appearance Of
children born Of the same parents.
And yet children born Of the same
parents are never exactly alike and
frequently vary to as great degree as
II they were not related. Not only do
they vary in physical conformation
in shape and size-whIch might be
accounted for on the ground that
they were reared under different con-
ditions-but they differ frequently at
birth in the color of the hair and
eyes and disposition.
But these variations are not so no.
ticeable among the wild things as
among the domestic animals and peo-
pie. There Is no question as to an an
imal's being influenced in its develop
ment by reason Of its surroundings,
it's exercise and its food. And. when
so Influenced, its peculiarities are
transmitted to its offspring.
Exercise probably has more to Go
with physical development of an ami
NAL than any other thing. This fact
&c don,or cfrofod tn fho raco of nor.
sons whose ancestors have followed
single occupation for many genera
lions. In the lower animals it Is also
known to be fact that acquired
characteristics are inherited. The
bird dog inherits not only the deep
lungs acquired by its ancestors, but
the instinct to point birds. The trot
and pace are acquired gaits with
horses and are freely transmitted
through inheritance, even to the for
nation of muscles conducive to speed.
The wild creatures do but few
things in making a living. The wolf
hunts after certain manner; the deer
grazes on the grass and buds of
plants; the quail picks up seeds and
bugs and worms. Over and over, gen.
GRAFTON after generation, these things
follow the same routine in securing
living. So they develop and transmit
to the offspring the degree of efficiency
needed to make living. So year after
year, generation after generation, the
members of the tribe, or pack, or
flock are kept at certain standard
and do not vary. But with domestic
animals, as where horses are used for
various purposes, where cows do not
live under identical conditions-and
with human beings, where there are
so many ways of making living.
variations are developed and trans
mitted to offspring.
But there are many uncertainties as
to what the offspring will be like. We
have not learned enough about the
laws of heredity even to state posi-
lively that the offspring of famous
race horse will have speed, although
we know that the tendency will be
toward speed The child of we'll
developed man and woman may be a
weakling, although the chances are IL
will be strong. And certainly we do
not know that the children of q very
brilliant man will be any more bril-
liant than other children. although,
according to the laws Of heredity, II
ought to be.