Comparison with 1859 |
|
variety
of
one
species
often
assumes
some
of
the
characters
of
an
allied
species, or
reverts
to
some
of
the
characters
of
an
early
progenitor
.—
|
These propositions will be most readily understood by looking to our domestic races. The most distinct breeds of pigeons,
in countries most
widely apart, present sub-varieties with reversed feathers on the head
and feathers
on the feet,—
characters not possessed by the aboriginal rock-pigeon; these then are analogous variations in two or more distinct races. The frequent presence of fourteen or even sixteen tail-feathers in the pouter,
may be considered as a variation representing the normal structure of another race, the fantail. I presume that no one will doubt that all such analogous variations are due to the several races of the pigeon having inherited from a common parent the same constitution and tendency to variation, when acted on by similar unknown influences. In the vegetable kingdom we have a case of analogous variation, in the enlarged stems, or roots as commonly called,
of the Swedish turnip and Ruta baga, plants which several botanists rank as varieties produced by cultivation from a common parent: if this be not so, the case will then be one of analogous variation in two so-called distinct species; and to these a third may be added, namely, the common turnip. According to the ordinary view of each species having been independently created, we should have to attribute this similarity in the enlarged stems of these three plants, not to the
vera
causa
of community of descent, and a consequent tendency to vary in a like manner, but to three separate yet closely related acts of creation. ↑2 blocks not present in 1859 1860 1861; present in 1866 1869 1872 | Many similar cases of analogous variation have been observed by Naudin in the great gourd-family, and by various authors in our cereals.
Similar cases occurring with insects under their
natural conditions have lately been discussed with much ability by Mr. Walsh, who has grouped them under his law of Equable Variability.
|
|
|
With pigeons, however, we have another case, namely, the occasional appearance in all the breeds, of slaty-blue birds with two black bars on the wings, a
white
rump, rump, 1859 1860 | croup, 1861 1866 | loins, 1869 1872 |
a bar at the end of the tail, with the outer
|
variety
variety
1859 1860 1861 |
Variety
1866 1869 |
Variety
1872 |
of
of
1859 1860 1861 1872 |
of
1866 1869 |
one
one
1859 1860 1861 1872 |
one
1866 1869 |
species
species
1859 1860 1861 |
Species
1866 1869 |
Species
1872 |
often
often
1859 1860 1861 1872 |
often
1866 1869 |
assumes
assumes
1859 1860 1861 1872 |
assumes
1866 1869 |
some of the characters of
some of the characters of
1859 1860 1861 |
some of the Characters of
1866 1869 |
a Character proper to
1872 |
an
an
1859 1860 1861 1872 |
an
1866 1869 |
allied
allied
1859 1860 1861 1872 |
allied
1866 1869 |
species,
species,
1859 1861 |
species
,
1860 |
Species,
1866 1869 |
Species
,
1872 |
or
or
1859 1860 1861 1872 |
or
1866 1869 |
reverts
reverts
1859 1860 1861 1872 |
reverts
1866 1869 |
to
to
1859 1860 1861 1872 |
to
1866 1869 |
some
some
1859 1860 1861 1872 |
some
1866 1869 |
of
of
1859 1860 1861 1872 |
of
1866 1869 |
the
the
1859 1860 1861 1872 |
the
1866 1869 |
characters
characters
1859 1860 1861 |
Characters
1866 1869 |
Characters
1872 |
of
of
1859 1860 1861 1872 |
of
1866 1869 |
an
an
1859 1860 1861 1872 |
an
1866 1869 |
early
early
1859 1860 1861 1872 |
early
1866 1869 |
progenitor
.—
progenitor
.—
1859 1861 |
progenitor.
— These propositions will be most readily understood by looking to our domestic races.
1860 |
Progenitor
. 1866 |
Progenitor
. 1869 |
Progenitor.
—
1872 |
|
These propositions will be most readily understood by looking to our domestic races. The most distinct breeds of
pigeons, pigeons, 1859 1860 1861 1866 1869 | the pigeon, 1872 |
in countries
most most 1859 1860 1861 1866 1869 | most 1872 |
widely apart, present sub-varieties with reversed feathers on the
head head 1859 1860 1861 1866 1869 | head, 1872 |
and
feathers feathers 1859 1860 1861 1866 1869 | with feathers 1872 |
on the
feet,— feet,— 1859 1860 1861 1872 | feet, — 1866 1869 |
characters not possessed by the aboriginal rock-pigeon; these then are analogous variations in two or more distinct races. The frequent presence of fourteen or even sixteen tail-feathers in the
pouter, pouter, 1859 1860 1861 | pouter 1866 1869 1872 |
may be considered as a variation representing the normal structure of another race, the fantail. I presume that no one will doubt that all such analogous variations are due to the several races of the pigeon having inherited from a common parent the same constitution and tendency to variation, when acted on by similar unknown influences. In the vegetable kingdom we have a case of analogous variation, in the enlarged stems, or
roots as commonly called, roots as commonly called, 1859 1860 1861 1866 1869 |
as commonly called roots, 1872 |
of the Swedish turnip and Ruta baga, plants which several botanists rank as varieties produced by cultivation from a common parent: if this be not so, the case will then be one of analogous variation in two so-called distinct species; and to these a third may be added, namely, the common turnip. According to the ordinary view of each species having been independently created, we should have to attribute this similarity in the enlarged stems of these three plants, not to the
vera
causa
of community of descent, and a consequent tendency to vary in a like manner, but to three separate yet closely related acts of creation. ↑2 blocks not present in 1859 1860 1861; present in 1866 1869 1872 | Many similar cases of analogous variation have been observed by Naudin in the great gourd-family, and by various authors in our cereals.
Similar cases occurring with insects under their
natural conditions have lately been discussed with much ability by Mr. Walsh, who has grouped them under his law of Equable Variability.
|
|
|
With pigeons, however, we have another case, namely, the occasional appearance in all the breeds, of slaty-blue birds with two black bars on the wings,
a a 1859 1860 1861 1866 | a 1869 1872 |
white
croup, croup, 1861 1866 | rump, 1859 1860 | loins, 1869 1872 |
a bar at the end of the tail, with the outer
|