| → seem 1859 1860 1861 1866 |
| appear in many cases 1869 1872 |
|
| → to the individual, 1859 1860 1861 1866 |
| OMIT 1869 1872 |
|
| → there are very many other correlations of growth, 1859 1860 1861 1866 |
| many cases of correlated variation, 1869 1872 |
|
| → understand. 1859 1860 1861 1866 |
| understand, undoubtedly occur. 1869 1872 |
|
| → which 1859 1860 1861 1866 |
| standing higher in the scale, and which 1869 1872 |
|
| → will be disregarded 1859 1860 1861 1866 |
| are not regulated 1869 1872 |
|
|
climate and food, &c., seem to have induced some slight modifications. Habit in producing constitutional
and use in
and disuse in weakening and diminishing organs,
→seem
to have been
potent in their effects. Homologous parts tend to vary in the same
and homologous parts tend to cohere. Modifications in hard parts and in external parts sometimes affect softer and internal parts. When one part is largely developed, perhaps it tends to draw nourishment from the adjoining parts; and every part of the structure which can be saved without detriment
→to the individual,
will be saved. Changes of structure at an early age
affect parts subsequently developed; and
→there are very many other correlations of growth,
the nature of which we are
unable to
→understand. Multiple parts are variable in number and in structure, perhaps arising from such parts not having been closely specialised
any particular function, so that their modifications have not been closely checked by natural selection. It
probably from this same
that organic beings low in the scale
are more variable than those
→which
have their whole organisation more
Rudimentary organs, from being useless,
→will be disregarded
by natural selection, and hence
are variable. Specific
that is, the characters which have come to differ since the several species of the same genus branched off from a common
are more variable than generic characters, or those which have long been inherited, and have not differed within this same period. In these remarks we have referred to special parts or organs being still variable, because they have recently varied and thus come to differ; but we have also seen in the second
that the same principle applies to the whole individual;
|
