Comparison with 1869 |
|
a special
acquirement or endowment, but as acquirement or endowment, but as 1869 1872 |
endowment, but is 1859 1860 1861 1866 |
incidental on
changes of an unknown nature in their sexual elements. changes of an unknown nature in their sexual elements. 1869 1872 |
slowly acquired modifications, more especially in the reproductive systems of the forms which are crossed. 1859 1860 1861 |
modifications, slowly impressed, by unknown means, on the reproductive systems of the parent-forms. 1866 |
|
Hybrids
and
Mongrels
compared, independently
of
their
fertility
.
fertility
. 1869 |
fertility
.—
1859 1860 1861 |
fertility
.
1866 |
fertility
. 1872 |
|
Independently of the question of fertility, the offspring of species when crossed
and of varieties when crossed may be compared in several other respects. Gärtner, whose strong wish was
to draw a marked
line of distinction
between species and varieties, could find very few
and, as it seems to me, quite unimportant differences between the so-called hybrid offspring of species, and the so-called mongrel offspring of varieties. And, on the other hand, they agree most closely in very
many important respects. |
|
I shall here discuss this subject with extreme brevity. The most important distinction is, that in the first generation mongrels are more variable than hybrids; but Gärtner admits that hybrids from species which have long been cultivated are often variable in the first generation; and I have myself seen striking instances of this fact. Gärtner further admits that hybrids between very closely allied species are more variable than those from very distinct species; and this shows that the difference in the degree of variability graduates away. When mongrels and the more fertile hybrids are propagated for several
generations, generations, 1869 1872 | generations 1859 1860 1861 1866 |
an extreme amount of variability in
the the 1869 1872 | their 1859 1860 1861 1866 |
offspring
in both cases is in both cases is 1869 1872 |
is 1859 1860 1861 1866 |
notori- ous;
but some few
instances of both instances of both 1869 1872 |
cases both of 1859 1860 1861 1866 |
hybrids and mongrels long retaining
a uniform a uniform 1869 1872 | uniformity of 1859 1860 1861 1866 |
character could be given. The variability, however, in the successive generations of mongrels is, perhaps, greater than in hybrids.
|
a special
endowment, but is endowment, but is 1859 1860 1861 1866 |
acquirement or endowment, but as 1869 1872 |
incidental on
modifications, slowly impressed, by unknown means, on the reproductive systems of the parent-forms. modifications, slowly impressed, by unknown means, on the reproductive systems of the parent-forms. 1866 |
slowly acquired modifications, more especially in the reproductive systems of the forms which are crossed. 1859 1860 1861 |
changes of an unknown nature in their sexual elements. 1869 1872 |
|
Hybrids
Hybrids
1866 1869 1872 |
Hybrids
1859 1860 1861 |
and
and
1866 1869 1872 |
and
1859 1860 1861 |
Mongrels
Mongrels
1866 1869 1872 |
Mongrels
1859 1860 1861 |
compared,
compared,
1866 1869 |
compared,
1859 1860 |
compared
,
1861 |
compared
,
1872 |
independently
independently
1866 1869 1872 |
independently
1859 1860 1861 |
of
of
1866 1869 1872 |
of
1859 1860 1861 |
their
their
1866 1869 1872 |
their
1859 1860 1861 |
fertility
.
fertility
.
1866 |
fertility
.—
1859 1860 1861 |
fertility
. 1869 |
fertility
. 1872 |
|
Independently of the question of fertility, the offspring of species
when crossed when crossed 1859 1860 1861 1866 1869 | when crossed 1872 |
and of varieties when crossed may be compared in several other respects. Gärtner, whose strong wish
it was it was 1861 1866 1869 1872 | was 1859 1860 |
to draw a
distinct distinct 1861 1866 1869 1872 | marked 1859 1860 |
line
....... 1861 1866 1869 1872 | of distinction 1859 1860 |
between species and varieties, could find very
few, few, 1861 1866 1869 1872 | few 1859 1860 |
and, as it seems to me, quite unimportant differences between the so-called hybrid offspring of species, and the so-called mongrel offspring of varieties. And, on the other hand, they agree most closely in
....... 1866 1869 1872 | very 1859 1860 1861 |
many important respects. |
|
I shall here discuss this subject with extreme brevity. The most important distinction is, that in the first generation mongrels are more variable than hybrids; but Gärtner admits that hybrids from species which have long been cultivated are often variable in the first generation; and I have myself seen striking instances of this fact. Gärtner further admits that hybrids between very closely allied species are more variable than those from very distinct species; and this shows that the difference in the degree of variability graduates away. When mongrels and the more fertile hybrids are propagated for several
generations generations 1859 1860 1861 1866 | generations, 1869 1872 |
an extreme amount of variability in
their their 1859 1860 1861 1866 | the 1869 1872 |
offspring
is is 1859 1860 1861 1866 |
in both cases is 1869 1872 |
notorious; notorious; 1860 1861 1866 1869 1872 | notori- ous; 1859 |
but some few
cases both of cases both of 1859 1860 1861 1866 |
instances of both 1869 1872 |
hybrids and mongrels long retaining
uniformity of uniformity of 1859 1860 1861 1866 | a uniform 1869 1872 |
character could be given. The variability, however, in the successive generations of mongrels is, perhaps, greater than in hybrids.
|