Comparison with 1869 |
|
grandfather grandfather 1859 1860 1861 1869 1872 | grand- father 1866 |
or grandmother or
....... 1869 1872 | other much 1859 | other 1860 1861 1866 |
more remote ancestor; why a peculiarity is often transmitted from one sex to both sexes, or to one sex alone, more commonly but not exclusively to the like sex. It is a fact of some
....... 1869 1872 | little 1859 1860 1861 1866 |
importance to us, that peculiarities appearing in the males of our domestic breeds are often transmitted
either exclusively,
or in a much greater degree, to
the males the males 1869 1872 | males 1859 1860 1861 1866 |
alone. A much more important rule, which I think may be trusted, is that, at whatever period of life a peculiarity first appears, it tends to
re-appear re-appear 1869 1872 | appear 1859 1860 1861 1866 |
in the offspring at a corresponding age, though sometimes earlier. In many cases this could not be otherwise:
thus the inherited peculiarities in the horns of cattle could appear only in the offspring when nearly mature; peculiarities in the silkworm
are known to appear at the corresponding caterpillar or cocoon stage. But hereditary diseases and some other facts make me believe that the rule has a wider extension, and that
when there is no apparent reason why a peculiarity should appear at any particular age, yet that it does tend to appear in the offspring at the same period at which it first appeared in the parent. I believe this rule to be of the highest importance in explaining the laws of embryology. These remarks are of course confined to the first
appearance
of the peculiarity, and not to its
primary cause,
which may have acted on the ovules or male
element; in nearly the same manner as in
the crossed
offspring from a short-horned cow by a long-horned bull, the greater length of horn,
though appearing late in life, is clearly due to the male element. |
|
Having alluded to the subject of reversion, I may here refer to a statement often made by naturalists — namely, that our domestic varieties, when run wild, gradually but
invariably invariably 1869 1872 | certainly 1859 1860 1861 1866 |
revert in character to their aboriginal stocks. Hence it has been argued that no
|
grand- father grand- father 1866 | grandfather 1859 1860 1861 1869 1872 |
or grandmother or
other other 1860 1861 1866 | other much 1859 | other 1869 1872 |
more remote ancestor; why a peculiarity is often transmitted from one sex to both sexes, or to one sex alone, more commonly but not exclusively to the like sex. It is a fact of some
little little 1859 1860 1861 1866 | little 1869 1872 |
importance to us, that peculiarities appearing in the males of our domestic breeds are often
transmitted, transmitted, 1866 1869 1872 | transmitted 1859 1860 1861 |
either
exclusively exclusively 1866 1869 1872 | exclusively, 1859 1860 1861 |
or in a much greater degree, to
males males 1859 1860 1861 1866 | the males 1869 1872 |
alone. A much more important rule, which I think may be trusted, is that, at whatever period of life a peculiarity first appears, it tends to
appear appear 1859 1860 1861 1866 | re-appear 1869 1872 |
in the offspring at a corresponding age, though sometimes earlier. In many cases this could not be
otherwise: otherwise: 1859 1860 1861 1866 1869 | otherwise; 1872 |
thus the inherited peculiarities in the horns of cattle could appear only in the offspring when nearly mature; peculiarities in the
silkworm silkworm 1859 1860 1861 1866 1869 | silk-worm 1872 |
are known to appear at the corresponding caterpillar or cocoon stage. But hereditary diseases and some other facts make me believe that the rule has a wider extension, and
that, that, 1866 1869 1872 | that 1859 1860 1861 |
when there is no apparent reason why a peculiarity should appear at any particular age, yet that it does tend to appear in the offspring at the same period at which it first appeared in the parent. I believe this rule to be of the highest importance in explaining the laws of embryology. These remarks are of course confined to the first
appearance
of the peculiarity, and not to
its its 1859 1860 1861 1866 1869 | the 1872 |
primary
cause, cause, 1859 1860 1861 1866 1869 | cause 1872 |
which may have acted on the ovules or
on the male on the male 1861 1866 1869 1872 |
male 1859 1860 |
element; in nearly the same manner as
in in 1859 1860 1861 1866 1869 | in 1872 |
the
...OMIT 1861 1866 1869 |
crossed 1859 1860 |
increased length of the horns in the 1872 |
offspring from a short-horned cow by a long-horned bull,
the greater length of horn, the greater length of horn, 1859 1860 1861 1866 1869 |
OMIT 1872 |
though appearing late in life, is clearly due to the male element. |
|
Having alluded to the subject of reversion, I may here refer to a statement often made by naturalists — namely, that our domestic varieties, when run wild, gradually but
certainly certainly 1859 1860 1861 1866 | invariably 1869 1872 |
revert in character to their aboriginal stocks. Hence it has been argued that no
|