397
modification. It should, further, be observed that the
modification inaugurated in this way is continued, so
that in a few generations there has taken place a change
which, in some cases, amounts to a transmutation of
species.
“ Mr. Winwood Reade, in speaking of the different animals and
plants introduced into West Africa, speaks of a marked change in
all:— 4 The horse rapidly deteriorates, and in some places cannot be
kept alive at all. The sheep change in other respects than their
wool. The very dogs which we should expect to bear the change as
well as their masters, alter under the baleful climate.’ 4 In process of
time,’ writes Bosman, 4 our dogs alter strangely here : their ears grow
long and stiff, like those of foxes, to which colour they also incline, so
that in three or four years they degenerate into very ugly creatures ;
and in three or four broods their barking turns into a howl.’ As to
plants, Mr. Reade says, 4 it is only on the borders of malarious
Africa—that is to say, in Angola and Senegambia—that most foreign
plants and vegetables can be made to live; and these, as Mr. Gabriel,
of Loanda, informed me, completely changed their nature when
planted in the African soil.’”—(Andrew Murray. The Geographical
Distribution of Mammals, p. 8.)
44 The effects of the climate of Europe on the American varieties (of
maize) is highly remarkable. Metzger obtained seed from various
parts of America, and cultivated several kinds in Germany. I will give
an abstract of the changes observed in one case, namely, with a tall
kind (Breit-korniger mays, Zea altissima) brought from the warmer
parts of America. During the first year the plants were twelve
feet high, and few seeds were perfected ; the lower seeds in the
ear kept true to their proper form, but the upper seeds became
slightly changed. In the second generation the plants were from
nine to ten feet in height, and ripened their seed better; the de
pression on the outer side of the seed had almost disappeared, and
the original beautiful white colour had become duskier. Some of the
seeds had even become yellow, and in their now rounded form they
approached common European maize. In the third generation nearly
all resemblance to the original and very distinct American parent-
form was lost. In the sixth generation this maize perfectly resembled
a European variety, described as the second sub-variety of the fifth
race. When Metzer published his book this variety was still culti
vated near Heidelberg, and could be distinguished from the common
kind only by a somewhat more vigorous growth. Analogous results
were obtained by the cultivation of another American race, the 4 white-