certain tropical
countries.[678] The _Rhododendron ciliatum_ produced at Kew flowers so
much larger and paler-coloured than those which it bears on its native
Himalayan mountain, that Dr. Hooker[679] would hardly have recognised
the species by the flowers alone. Many similar facts with respect to
the colour and size of flowers could be given.

The experiments of Vilmorin and Buckman on carrots and parsnips prove
that abundant nutriment produces a definite and inheritable effect on
the so-called roots, with scarcely any change in other parts of the
plant. Alum directly influences the colour of the flowers of the
Hydrangea.[680] Dryness seems generally to favour the hairyness or
villosity of plants. Gaertner found that hybrid Verbascums became
extremely woolly when grown in pots. Mr. Masters, on the other hand,
states that the _Opuntia leucotricha_ "is well clothed with beautiful
white hairs when grown in a damp heat; but in a dry heat exhibits none
of this peculiarity."[681] Slight variations of many kinds, not worth
specifying in detail, are retained only as {278} long as plants are
grown in certain soils, of which Sageret[682] gives from his own
experience some instances. Odart, who insists strongly on the
permanence of the varieties of the grape, admits[683] that some
varieties, when grown under a different climate or treated differently,
vary in an extremely slight degree, as in the tint of the fruit and in
the period of ripening. Some authors have denied that grafting causes
even the slightest difference in the scion; but there is sufficient
evidence that the fruit is sometimes slightly affected in size and
flavour, the leaves in duration, and the flowers in appearance.[684]

With animals there can be no doubt, from the facts given in the first
chapter, that European dogs deteriorate in India, not only in their
instincts but in structure; but the changes which they undergo are of
such a nature, that they may be partly due to reversion to a primitive
form, as in the case of feral animals. In parts of India the turkey
becomes reduced in size, "with the pendulous appendage over the beak
enormously developed."[685] We have seen how soon the wild duck, when
domesticated, loses its true character, from the effects of abundant or
changed food, or from taking little exercise. From the direct