Rocky Mountain husbandman. [volume] (Diamond City, Mont.) 1875-1943, 1878-08-22
LIV { STOCK.
THEORY OF LINE BREEDING.

made 1or crossing, and Ii we consider only
the absurdities of those who advocate {
practice, it is not difficult to place any sys
TEN of breeding in an unfavorable light
but when we remember that, in the forma.
tion of nearly all our best breeds of animals
long and close %in-and-in breeding was prac
ticed, there certainly appears ground tor
looking at the matter from &. reasonable and
unbiased standpoint. The great law that
,"likc produces like" that is, that every
thing inherited by the offspring must have
previously existed in the ancestors, covers
the whole subject OF breeding, and how it
can be supposed that an animal can trans
init that which it does not possess, whether
by in-and-in breeding or crossing, is incom-
.prehensible. 1T those who favor line breed
Ing are willing to admit this, is it asking
too much if we expect our opponents to do
the same? What we claim for in-and-in
breeding is that it increases the parental
power of reproducing themselves in their
offspring, and in order to successfully dis
pute this, it is necessary to over. brow the
whole theory that like produces like-that
parents transmit that which they possess.
If We pair a thoroughbred with "a Perche-
ron, What can we expect? The offspring
cannot be like both parents, because they
are unlike; but long experience has demon
strated that it may closely resemble either
parent; that it may vary all the way be-
tween the parental extremes or, finally,
that it may revert, to- greater or less extent,
to the form of some remote ANCESTOR. That
is to say, such a union does not admit of any
certainty rs TO the form and character OF the
offspring. If, now, we pair two thorough
oreds, or two ShOrt-Horns, the produce will
Inevitably be Il thoroughbred or u Short
Horn. Why? Because the parents are alike
IN the characters which are. peculiar to these
breeds. nnlNt, go a step farther; the mem
bers Of one strain OF Short,Horns are good
mixers. those OF another are not. How shall
we breed to perpetuate the ~lnilk-producing
aptitude? Evidently by breeding within tie
milking strain for if we go beyond, we
have the same causes for variation-tl,e same
uncertainty OF results-as in crossing the
thoroughbred and Percheron. This mucl,
we think must be admitted, and, if so, it
shows that a family may have the same
:" distinctive claracrers that are usually at
tribute to Il breed or race - and hence ari-
ses 4 necessity for lire Or family breeding.
Again. the simple fact that two animals
have certain characteristics apparently in
common, is no surety that if paired they will
transmit them to their offspring; there are
certain internal or physiological tendencies,
OF which we have little cognizance, except !
from their effects. which may be antagonis-
tic and cause reversion. Thus two non-sit-
ting varieties of fuWls, though alike in this
respect, when bred to1etherolten revert to
the ancestral character of brooding; and SO
the nnion OF different strains of the same
breed often causes partial reversion, espec-
Tally IL color, as many Of Of our breeders Of
birds have found to their cost. But
when bred within itself, a variety of ever
lasting layers will not produce broody Off
nor will an established strain Of any
variety produce reversions of color. That |
r 10 say. The union OF animals that are UNI ,
like, either anatomically or plIysiologically, |
they belong to different breeds, TO c
varieties OF the same breed, or even :
TO different strains Of the same variety. pro- t
variable offspring, and that which is S
peculiarly subject TO reversion. G
But how are we TO know that animals are t
in characters or tendencies that arc be- e
yond our penetration? If wo animals are il
4 .scelded from the same parents. The iniIu- i
,nce OF the remote ancestors mutt be identi- t