wn, renamed.
There are possibly a hundred or more grapes now under cultivation
wholly or in part from Vulpina, most of them hybrids with the American
Labrusca and the European Vinifera, with both of which it hybridizes
freely.

_Domesticated species of minor importance._

In the preceding paragraphs we have seen that four species of grapes
constitute the foundation of American viticulture. Nine other species
furnish pure-bred varieties and many hybrids with the four chief
species or among themselves. These are _V. rupestris_, _V. Longii_,
_V. Champinii_, _V. Munsoniana_, _V. cordifolia_, _V. candicans_, _V.
bicolor_, _V. monticola_ and _V. Berlandieri_. Several of these nine
species are of value in the vineyard or for stocks upon which to graft
other grapes. The domestication of all of these is just begun, and
each year sees them more and more in use in the vineyards of the
country.

[Illustration: PLATE I.--Two views of vineyards in California. _Top_,
a vineyard in the orchard region of central California; _bottom_, a
vineyard in southern California.]

CHAPTER II

GRAPE REGIONS AND THEIR DETERMINANTS

Happily, the grape in its great diversity of forms accommodates itself
to many conditions, so that some variety of the several cultivated
species will produce fruit for home use, if not as a market commodity,
in every part of America adapted to general agriculture. But
commercial grape-growing on this continent is confined to a few
regions, in each of which it is profitable only in ideal situations.
In fact, few other agricultural industries are more definitely
determined by environment than the grape-industry. Where are the grape
regions of America? What determines the suitability of a region for
grape-growing? Answers to these questions furnish clews to the culture
of this fruit and help in estimating the potentialities of a new
region or of a location for grape-growing.

THE GRAPE REGIONS OF AMERICA

There are four chief grape-growing regions in North America, with
possibly twice as many more subsidiary ones. These several regions,
each of which has its distinct varieties and to less extent distinct
species, and in each of which grapes are grown for somewhat widely
different purposes, give a great variety of industrial conditions to
the grape-growing of the continent. Nevertheless, the regions have
much in common in their environment. It is from their differences and
similarities that most can be