| → in both cases is 1869 1872 |
| is 1859 1860 1861 1866 |
|
| → instances of both 1869 1872 |
| cases both of 1859 1860 1861 1866 |
|
| → OMIT 1869 1872 |
| in most cases 1859 1860 1861 1866 |
|
| → which 1869 1872 |
| and therefore we might expect that such variability 1859 1860 1861 1866 |
|
| → be added to 1869 |
| be super-added to 1859 1861 |
| be superadded to 1860 1866 |
| would augment 1872 |
|
| → OMIT 1869 1872 |
| cross or in the first 1859 1860 1861 1866 |
|
| → OMIT 1869 |
| their extreme variability in 1859 1860 1861 1866 |
| that in 1872 |
|
| → of one of 1869 1872 |
| on 1859 1860 1861 1866 |
|
| → OMIT 1869 1872 |
| it is due to 1859 1860 1861 1866 |
|
| → fails under these circumstances to perform 1869 1872 |
| being thus often rendered either impotent or at least incapable of 1859 1860 1861 1866 |
|
| → identical in all respects with 1869 |
| identical with 1859 1860 1861 1866 |
| closely similar in all respects to 1872 |
|
|
variability in
offspring
→in both cases is
but some few
→instances of both
hybrids and mongrels long retaining
character could be given. The variability, however, in the successive generations of mongrels is, perhaps, greater than in hybrids. |
|
| This greater variability
mongrels than
hybrids does not seem
at all surprising. For the parents of mongrels are varieties, and mostly domestic varieties (very few experiments having been tried on natural varieties), and this implies
→OMIT
that there has been recent
→which
would often continue and
→be added to
that arising from the
act of crossing. The slight
of
in
the first
→OMIT
generation, in contrast with
→OMIT
the succeeding generations, is a curious fact and deserves attention. For it bears on
the view which I have taken
→of one of
the
of ordinary
namely, that
→OMIT
the reproductive system
eminently sensitive to
conditions of life,
→fails under these circumstances to perform
its proper function of producing offspring
→identical in all respects with
the parent-form. Now hybrids in the first generation are descended from species (excluding those
which have not had their reproductive systems in any way affected, and they are not variable; but hybrids themselves have their reproductive systems seriously affected, and their descendants are highly variable. |
|
| But to return to our comparison of mongrels and hybrids: Gärtner states that mongrels are more liable than hybrids to revert to either parent-form; but this, if it be true, is certainly only a difference in degree. Moreover, Gärtner expressly states that hybrids from
plants are more subject to reversion than hybrids from species in their natural state; and this probably explains the singular difference in the results
|
