are more easily
propagated than the American species.

Because of these points of superiority in the Old World grape, since
Valk, Allen and Rogers showed the way, American grape-breeders have
sought to unite by hybridization the good characters of the Old World
grape with those of the American. Nearly half of the 2000 grapes
cultivated in eastern America have more or less European blood in
them. Yet, despite the efforts of the breeders, few of these hybrids
have commercial value. Whether because they are naturally better
fixed, or long cultivation has more firmly established them, the vine
characters of _Vitis vinifera_ more often appear in varieties arising
as primary hybrids between that and the native species, and the
weaknesses of the foreign grape, which prevent their cultivation in
America, crop out. Hybrids in which the vinifera blood is more
attenuated, as secondary or tertiary crosses, give better results.

Several secondary hybrids now rank among the best of the cultivated
grapes. Examples are Brighton and Diamond. The first is a cross
between Diana-Hamburg, a hybrid of a Vinifera and a Labrusca, crossed
in its turn with Concord, a Labrusca; the second is a cross between
Iona, also a hybrid between a Vinifera and a Labrusca, crossed with
Concord. Both were grown from seed planted by Jacob Moore, Brighton,
New York, in 1870. Brighton was the first secondary hybrid to attract
the attention of grape-breeders, and its advent marked an important
step in breeding grapes.

The signal success achieved by hybridizers of the European grape with
native species quickly led to similar amalgamations among American
species. Jacob Rommel, of Morrison, Missouri, beginning work about
1860, hybridized Labrusca and Vulpina grapes so successfully that a
dozen or more of his varieties are still cultivated. All are
characterized by great vigor and productiveness; and, although they
lack the qualities which make good table-grapes, they are among the
best for wine-making. Rommel has had many followers in hybridizing
native species, chief of whom was the late T. V. Munson, Fig. 50,
Denison, Texas, who literally made every combination of grapes
possible, grew thousands of seedlings and produced many valuable
varieties.

[Illustration: FIG. 50. T. V. Munson.]

_Improvement by selection._

Selection, continued through successive generations, so important in
the improvement of field and garden plants, has played but small part
in