Comparison with 1872 |
|
CHAPTER I. |
VARIATION UNDER DOMESTICATION. |
Causes of Variability— Effects of
Habit and the use or disuse of Parts— Correlated Variation— Habit and the use or disuse of Parts— Correlated Variation— 1872 |
Habit— Correlation of Growth— 1859 1860 1861 1866 |
Habit— Correlated Variation— 1869 |
Inheritance— Character of Domestic Varieties— Difficulty of distinguishing between Varieties and Species— Origin of Domestic Varieties from one or more Species— Domestic Pigeons, their Differences and Origin— Principle
of Selection
anciently followed, its
Effects— Methodical and Unconscious Selection— Unknown Origin of our Domestic Productions— Circumstances favourable to Man's power of Selection. |
Causes
of
Variability.
|
WHEN we look to
the individuals of the same variety or sub-variety of our older cultivated plants and animals, one of the first points which strikes us,
is, that they generally differ
more more 1860 1861 1866 1872 | much more 1859 | more 1869 |
from each other,
than than 1859 1860 1861 1866 1872 | more than 1869 |
do the individuals of any one species or variety in a state of nature. When
we reflect on the vast diversity of the plants and animals which have been cultivated, and which have varied during all ages under the most different climates and treatment, I think
we are driven to conclude that this greater
variability is simply
due to our domestic productions having been raised under conditions of life not so uniform as, and somewhat different from, those to which the parent-species have
been exposed under nature. There
is, is, 1859 1872 | is 1860 1861 1866 1869 |
also,
....... 1872 | I think, 1859 1860 1861 1866 1869 |
some probability in the view propounded by Andrew Knight, that this variability may be partly connected with excess of food. It seems pretty
clear that organic beings must be exposed during several generations to the
new conditions of life
to cause any
great great 1872 | appreciable 1859 1860 1861 1866 1869 |
amount of variation; and that
when the organisation has once begun to
|
CHAPTER I. |
VARIATION UNDER DOMESTICATION. |
Causes of Variability— Effects of
Habit— Correlated Variation— Habit— Correlated Variation— 1869 |
Habit— Correlation of Growth— 1859 1860 1861 1866 |
Habit and the use or disuse of Parts— Correlated Variation— 1872 |
Inheritance— Character of Domestic Varieties— Difficulty of distinguishing between Varieties and Species— Origin of Domestic Varieties from one or more Species— Domestic Pigeons, their Differences and Origin—
Principles Principles 1866 1869 1872 | Principle 1859 1860 1861 |
of
Selection, Selection, 1866 1869 1872 | Selection 1859 1860 1861 |
anciently followed,
their their 1866 1869 1872 | its 1859 1860 1861 |
Effects— Methodical and Unconscious Selection— Unknown Origin of our Domestic Productions— Circumstances favourable to Man's power of Selection. |
Causes
of
Variability.
|
WHEN we
compare compare 1869 1872 | look to 1859 1860 1861 1866 |
the individuals of the same variety or sub-variety of our older cultivated plants and animals, one of the first points which strikes
us us 1869 1872 | us, 1859 1860 1861 1866 |
is, that they generally differ
....... 1869 | much more 1859 | more 1860 1861 1866 1872 |
from each
other other 1860 1861 1866 1869 1872 | other, 1859 |
more than more than 1869 | than 1859 1860 1861 1866 1872 |
do the individuals of any one species or variety in a state of nature.
And if And if 1869 1872 | When 1859 1860 1861 1866 |
we reflect on the vast diversity of the plants and animals which have been cultivated, and which have varied during all ages under the most different climates and treatment,
....... 1869 1872 | I think 1859 1860 1861 1866 |
we are driven to conclude that this
great great 1860 1861 1866 1869 1872 | greater 1859 |
variability is
....... 1869 1872 | simply 1859 1860 1861 1866 |
due to our domestic productions having been raised under conditions of life not so uniform as, and somewhat different from, those to which the parent-species
had had 1869 1872 | have 1859 1860 1861 1866 |
been exposed under nature. There
is is 1860 1861 1866 1869 | is, 1859 1872 |
also,
I think, I think, 1859 1860 1861 1866 1869 | I think, 1872 |
some probability in the view propounded by Andrew Knight, that this variability may be partly connected with excess of food. It seems
....... 1869 1872 | pretty 1859 1860 1861 1866 |
clear that organic beings must be exposed during several generations to
....... 1869 1872 | the 1859 1860 1861 1866 |
new conditions
....... 1869 1872 | of life 1859 1860 1861 1866 |
to cause any
appreciable appreciable 1859 1860 1861 1866 1869 | great 1872 |
amount of variation; and
that, that, 1866 1869 1872 | that 1859 1860 1861 |
when the organisation has once begun to
|