ull up
the false plants or "rogues" as they are called. It has already been
remarked, that some few seedling apples and pears generally resemble, but
apparently are not identical with, the wild trees from which they are
descended. In our turnip[73] and carrot-beds a few plants often
"break"--that is, flower too soon; and their roots are generally found to
be hard and stringy, as in the parent-species. By the aid of a little
selection, carried on during a few generations, most of our cultivated
plants could probably be brought back, without any great change in their
conditions of life, to a wild or nearly wild condition: Mr. Buckman has
effected this with the parsnip;[74] {32} and Mr. Hewett C. Watson, as he
informs me, selected, during three generations, "the most diverging plants
of Scotch kail, perhaps one of the least modified varieties of the cabbage;
and in the third generation some of the plants came very close to the forms
now established in England about old castle-walls, and called indigenous."

* * * * *

_Reversion in Animals and Plants which have run wild._--In the cases
hitherto considered, the reverting animals and plants have not been exposed
to any great or abrupt change in their conditions of life which could have
induced this tendency; but it is very different with animals and plants
which have become feral or run wild. It has been repeatedly asserted in the
most positive manner by various authors, that feral animals and plants
invariably return to their primitive specific type. It is curious on what
little evidence this belief rests. Many of our domesticated animals could
not subsist in a wild state; thus, the more highly improved breeds of the
pigeon will not "field" or search for their own food. Sheep have never
become feral, and would be destroyed by almost every beast of prey. In
several cases we do not know the aboriginal parent-species, and cannot
possibly tell whether or not there has been any close degree of reversion.
It is not known in any instance what variety was first turned out; several
varieties have probably in some cases run wild, and their crossing alone
would tend to obliterate their proper character. Our domesticated animals
and plants, when they run wild, must always be exposed to new conditions of
life, for, as Mr. Wallace[75] has well remarked, they have to obtain their
own food, and are exposed to competition with the native productions. Under
the