nt parts of South America as differing
in several respects. In Louisiana the pig[76] has run wild, and is said
to differ a little in form, and much in colour, from the domestic
animal, yet does not closely resemble the wild boar of Europe. With
pigeons and fowls,[77] it is not known what variety was first turned
out, nor what character the feral birds have assumed. The guinea-fowl
in the West Indies, when feral, seems to vary more than in the
domesticated state.

With respect to plants run wild, Dr. Hooker[78] has strongly insisted
on what slight evidence the common belief in their power of reversion
rests. Godron[79] describes wild turnips, carrots, and celery; but
these plants in their cultivated state hardly differ from their wild
prototypes, except in the {34} succulency and enlargement of certain
parts,--characters which would be surely lost by plants growing in a
poor soil and struggling with other plants. No cultivated plant has run
wild on so enormous a scale as the cardoon (_Cynara cardunculus_) in La
Plata. Every botanist who has seen it growing there, in vast beds, as
high as a horse's back, has been struck with its peculiar appearance;
but whether it differs in any important point from the cultivated
Spanish form, which is said not to be prickly like its American
descendant, or whether it differs from he wild Mediterranean species,
which is said not to be social, I do not know.

* * * * *

_Reversion to Characters derived from a Cross, in the case of
Sub-varieties, Races, and Species._--When an individual having some
recognizable peculiarity unites with another of the same sub-variety, not
having the peculiarity in question, it often reappears in the descendants
after an interval of several generations. Every one must have noticed, or
heard from old people of children closely resembling in appearance or
mental disposition, or in so small and complex a character as expression,
one of their grandparents, or some more distant collateral relation. Very
many anomalies of structure and diseases,[80] of which instances have been
given in the last chapter, have come into a family from one parent, and
have reappeared in the progeny after passing over two or three generations.
The following case has been communicated to me on good authority, and may,
I believe, be fully trusted: a pointer-bitch produced