Comparison with 1869 |
|
other; but only a single head produced any seed, and this one head produced only five grains. Manipulation in this case
could not have been injurious, as the plants have separated sexes. No one, I believe, has suspected that these varieties of maize are distinct species; and it is important to notice that the hybrid plants thus raised were themselves
perfectly
fertile; so that even Gärtner did not venture to consider the two varieties as specifically distinct. |
|
Girou de Buzareingues crossed three varieties of gourd, which like the maize has separated sexes, and he asserts that their mutual fertilisation is by so much the less easy as their differences are greater. How far these experiments may be trusted, I know not; but the forms experimentised
on,
are ranked by Sagaret,
who mainly founds his classification by the test of infertility, as varieties.
|
|
The following case is far more remarkable, and seems at first
quite quite 1859 1860 1861 1866 1869 | quite 1872 |
incredible; but it is the result of an astonishing number of experiments made during many years on nine species of Verbascum, by so good an observer and so hostile a witness,
as Gärtner:
namely, namely, 1859 1860 1861 1866 1869 | namely 1872 |
that yellow
and white varieties of the same species of Verbascum when
intercrossed
produce less seed,
than do either
coloured varieties
when fertilised with pollen from their own coloured flowers.
Moreover, he asserts that
when yellow and white varieties of one species are crossed with yellow and white varieties of a
distinct
species, more seed is produced by the crosses between the same
coloured flowers, than between those which are differently coloured. Mr.
Scott,
also,
has experimented on the species and varieties of Verbascum; and although unable to confirm
Gärtners Gärtners 1869 | Gärtner's 1872 |
results on the crossing of the distinct species, he finds that the dissimilarly coloured varieties of the same species yield fewer seeds, in the proportion of 86 to 100, than the similarly coloured varieties. Yet these varieties of Verbascum present no other difference besides the mere
colour of the
flower;
and one variety can sometimes be raised from the seed of the
other.
↑1 blocks not present in 1866 1869 1872; present in 1859 1860 1861 | From observations
which I have made on certain varieties of hollyhock, I am inclined to suspect that they present analogous facts.
|
|
|
Kölreuter, whose accuracy has been confirmed by every subsequent observer, has proved the remarkable fact, that one variety
of the common tobacco is
more fertile,
when
crossed with a widely distinct species,
than are the other varieties.
He experimentised
on five
forms, forms, 1859 1860 1861 1866 1869 | forms 1872 |
which are commonly reputed to be varieties, and which he tested by the severest trial, namely, by reciprocal crosses, and he found their mongrel offspring perfectly fertile. But one of these five varieties, when used either as father
or mother, and crossed with the Nicotiana glutinosa, always yielded hybrids not so sterile as those which were produced from the four other varieties when crossed with N. glutinosa. Hence the reproductive system
|
other; but only a single head produced any seed, and this one head produced only five grains. Manipulation in this
case case 1859 1860 1866 1869 1872 | ease 1861 |
could not have been injurious, as the plants have separated sexes. No one, I believe, has suspected that these varieties of maize are distinct species; and it is important to notice that the hybrid plants thus raised were themselves
perfectly
fertile; so that even Gärtner did not venture to consider the two varieties as specifically distinct. |
|
Girou de Buzareingues crossed three varieties of gourd, which like the maize has separated sexes, and he asserts that their mutual fertilisation is by so much the less easy as their differences are greater. How far these experiments may be trusted, I know not; but the forms
experimented experimented 1861 1866 1869 1872 | experimentised 1859 1860 |
on on 1861 1866 1869 1872 | on, 1859 1860 |
are ranked by
Sageret, Sageret, 1866 1869 1872 | Sagaret, 1859 1860 1861 |
who mainly founds his classification by the test of infertility, as
varieties, and Naudin has come to the same conclusion. varieties, and Naudin has come to the same conclusion. 1866 1869 1872 |
varieties. 1859 1860 1861 |
|
|
The following case is far more remarkable, and seems at first
....... 1872 | quite 1859 1860 1861 1866 1869 |
incredible; but it is the result of an astonishing number of experiments made during many years on nine species of Verbascum, by so good an observer and so hostile a
witness witness 1861 1866 1869 1872 | witness, 1859 1860 |
as Gärtner:
namely namely 1872 | namely, 1859 1860 1861 1866 1869 |
that
the yellow the yellow 1869 1872 | yellow 1859 1860 1861 1866 |
and white varieties
...OMIT 1869 1872 |
of the same species of Verbascum when 1859 1860 1861 1866 |
when crossed when crossed 1869 1872 | intercrossed 1859 1860 1861 1866 |
produce less
seed seed 1869 1872 | seed, 1859 1860 1861 1866 |
than
the similarly the similarly 1869 1872 | do either 1859 1860 1861 | does either 1866 |
coloured
varieties varieties 1859 1860 1861 1869 1872 | variety 1866 |
of the same species. of the same species. 1869 1872 |
when fertilised with pollen from their own coloured flowers. 1859 1860 1861 |
when fertilised with pollen from its own coloured flowers. 1866 |
Moreover, he asserts
that, that, 1866 1869 1872 | that 1859 1860 1861 |
when yellow and white varieties of one species are crossed with yellow and white varieties of a
distinct
species, more seed is produced by the crosses between the
similarly similarly 1860 1861 1866 1869 1872 | same 1859 |
coloured flowers, than between those which are differently coloured. Mr.
Scott
also
has experimented on the species and varieties of Verbascum; and although unable to confirm
Gärtner's Gärtner's 1872 | Gärtners 1869 |
results on the crossing of the distinct species, he finds that the dissimilarly coloured varieties of the same species yield fewer seeds, in the proportion of 86 to 100, than the similarly coloured varieties. Yet these varieties
differ in no respect except in the differ in no respect except in the 1869 1872 |
of Verbascum present no other difference besides the mere 1859 1860 1861 1866 |
colour of
their their 1869 1872 | the 1859 1860 1861 1866 |
flowers; flowers; 1869 1872 | flower; 1859 1860 1861 1866 |
and one variety can sometimes be raised from the seed of
....... 1869 1872 | the 1859 1860 1861 1866 |
another. another. 1869 1872 | other. 1859 1860 1861 1866 |
↑1 blocks not present in 1866 1869 1872; present in 1859 1860 1861 | From observations
which I have made on certain varieties of hollyhock, I am inclined to suspect that they present analogous facts.
|
|
|
Kölreuter, whose accuracy has been confirmed by every subsequent observer, has proved the remarkable fact, that one
particular variety particular variety 1869 1872 | variety 1859 1860 1861 1866 |
of the common tobacco
was was 1869 1872 | is 1859 1860 1861 1866 |
more
fertile fertile 1869 1872 | fertile, 1859 1860 1861 1866 |
than the other varieties, when than the other varieties, when 1869 1872 |
when 1859 1860 1861 1866 |
crossed with a widely distinct
species. species. 1869 1872 | species, 1859 1860 1861 1866 |
....... 1869 1872 | than 1859 1860 1861 1866 |
....... 1869 1872 | are 1859 1860 1861 1866 |
....... 1869 1872 | the 1859 1860 1861 1866 |
....... 1869 1872 | other 1859 1860 1861 1866 |
....... 1869 1872 | varieties. 1859 1860 1861 1866 |
He
experimented experimented 1861 1866 1869 1872 | experimentised 1859 1860 |
on five
forms forms 1872 | forms, 1859 1860 1861 1866 1869 |
which are commonly reputed to be varieties, and which he tested by the severest trial, namely, by reciprocal crosses, and he found their mongrel offspring perfectly fertile. But one of these five varieties, when used either as
the father the father 1869 1872 | father 1859 1860 1861 1866 |
or mother, and crossed with the Nicotiana glutinosa, always yielded hybrids not so sterile as those which were produced from the four other varieties when crossed with N.
glutinosa. glutinosa. 1859 1860 1866 1869 1872 |
glutinosa. Hence the reproductive system of this one variety must have been in some manner and in some degree modified. 1861 |
Hence the reproductive system
|