common or
musk duck. No case is {46} known of this latter bird having escaped and
become wild in Europe or Asia, except, according to Pallas, on the Caspian
Sea; and the common domestic duck only occasionally becomes wild in
districts where large lakes and fens abound. Nevertheless, a large number
of cases have been recorded[109] of hybrids from these two ducks, although
so few are reared in comparison with purely-bred birds of either species,
having been shot in a completely wild state. It is improbable that any of
these hybrids could have acquired their wildness from the musk-duck having
paired with a truly wild duck; and this is known not to be the case in
North America; hence we must infer that they have reacquired, through
reversion, their wildness, as well as renewed powers of flight.

These latter facts remind us of the statements, so frequently made by
travellers in all parts of the world, on the degraded state and savage
disposition of crossed races of man. That many excellent and kind-hearted
mulattos have existed no one will dispute; and a more mild and gentle set
of men could hardly be found than the inhabitants of the island of Chiloe,
who consist of Indians commingled with Spaniards in various proportions. On
the other hand, many years ago, long before I had thought of the present
subject, I was struck with the fact that, in South America, men of
complicated descent between Negroes, Indians, and Spaniards, seldom had,
whatever the cause might be, a good expression.[110] Livingstone,--and a
more unimpeachable authority cannot be quoted,--after speaking of a
half-caste man on the Zambesi, described by the Portuguese as a rare
monster of inhumanity, remarks, "It is unaccountable why half-castes, such
as he, are so much more cruel than the Portuguese, but such is undoubtedly
the case." An inhabitant remarked to Livingstone, "God made white men, and
God made black men, but the Devil made half-castes."[111] When two races,
both {47} low in the scale, are crossed, the progeny seems to be eminently
bad. Thus the noble-hearted Humboldt, who felt none of that prejudice
against the inferior races now so current in England, speaks in strong
terms of the bad and savage disposition of Zambos, or half-castes between
Indians and Negroes; and this conclusion has been arrived at by various
observers.[112] From these facts we may perhaps infer that the degraded
state of so many half-castes is in part due to reversion to a prim