| → enter on the copious 1859 1860 1861 1866 |
| give the 1869 1872 |
|
| → on 1859 1860 1861 1866 |
| and elsewhere published on 1869 1872 |
|
| → which seldom produce young; whereas 1861 1866 1869 1872 |
| whereas, 1859 |
| whereas 1860 |
|
| → not perfectly like 1859 1860 1861 1866 |
| somewhat unlike 1869 1872 |
|
| ↑ 5 blocks not present in 1859 1860 1861 1866; present in 1869 1872 |
| I may add, that as some organisms breed freely under the most unnatural conditions (for instance, rabbits and ferrets kept in hutches), showing that their reproductive organs are not affected;
so will some animals and plants withstand domestication or cultivation, and vary very slightly — perhaps hardly more than in a state of nature.
Some naturalists have maintained that all variations are connected with the act of sexual reproduction; but this is certainly an error; for I have given in another work a long list of "sporting plants,"
as they are called by gardeners; — that is, of plants which have suddenly produced a single bud with a new and sometimes widely different character from that of the other buds on the same plant.
These bud-variations,
as they may be named, can be propagated by grafts, offsets, &c., and sometimes by seed.
They occur rarely under nature, but far from rarely
under culture.
As a single bud out of the
many thousands
produced year after year under uniform conditions on the same tree,
has been known suddenly to assume a new character; and as buds on distinct trees, growing under different conditions, have sometimes yielded nearly the same variety — for instance, buds on peach-trees producing nectarines, and buds on common roses producing moss-roses — we clearly see that the nature of the conditions is of quite
subordinate importance in comparison with the nature of the organism in determining each particular form of variation; — of
not more importance than the nature of the spark
by which a mass of com-
bustible
matter is ignited, has in determining the nature of the flames.
|
|
| ←Subtitle not present 1859 1860 1861 1866 1869 1872
|
| →enter on the copious
details which I have collected
→on
this curious subject; but to show how singular the laws are which determine the reproduction of animals under confinement, I may
mention that carnivorous animals, even from the tropics, breed in this country pretty freely under confinement, with the exception of the plantigrades or bear
→which seldom produce young; whereas
carnivorous birds, with the rarest exceptions, hardly ever lay fertile eggs. Many exotic plants have pollen utterly worthless, in the same
condition as in the most sterile hybrids. When, on the one hand, we see domesticated animals and plants, though often weak and sickly,
breeding
freely under confinement; and when, on the other hand, we see individuals, though taken young from a state of
perfectly tamed,
and healthy (of which I could give numerous instances), yet having their reproductive system so seriously affected by unperceived causes as to fail
we need not be surprised at this system, when it does act under confinement, acting
and producing offspring
→not perfectly like
their
↑ →
|
|
| Sterility has been said to be the bane of horticulture; but on this view we owe variability to the same cause which produces sterility; and variability is the source of all the choicest productions of the garden. I may add, that as some organisms will breed
freely under the most unnatural conditions (for instance, the rabbit and ferret kept in hutches), showing that their reproductive system has not been thus affected; so will some animals and plants withstand domestication or cultivation, and vary very slightly — perhaps hardly more than in a state of nature. |
|
| A long list could easily be given of "sporting plants;" by this term gardeners mean a single bud or offset,
|
