Since this work is not written from the standpoint of the botanist but of the horticulturist, no effort has been made to revise the botany of the grape. But it has been necessary to select some arrangement of species in order to make such disposition of the cultivated varieties that their characters and relationships can best be shown. In making a choice of the several recent classifications of American grapes, three main considerations have been in mind: First, that the arrangement should separate the species in the genus freely, thus decreasing the size of the groups so that they may be more easily studied. Second, that it should show as clearly as possible the relationships of the various groups and of their development--the evolution of the grape. Third, that it be an arrangement in good standing with botanists and horticulturists. After having examined all American classifications of grapes and all recent European ones, Bailey's classification, as set forth in his monograph of the Vitaceae in _Gray's Synoptical Flora_, in the _Evolution of our Native Fruits_, and in the _Cyclopedia of American Horticulture_, was adopted.
_The Grapes of New York_ makes its chief contribution to the pomology of the country in the description of varieties. The authors have tried to study varieties from every point of view, not alone nor chiefly, it must be said, with regard to their cultural value; for most of the varieties pass out of cultivation and such information would be worthless within a few years at most. But, rather, the effort has been to determine what elementary or unit characters the grape possesses as shown in its botanical and horticultural groups. The Twentieth Century begins with the unanimous judgment of scientists that the characters of plants are independent entities which are thrown into various relationships with each other in individuals and groups of individuals. This conception of unit characters lies at the foundation of plant improvement. We are but beginning the breeding of American grapes and it has seemed to the writer that the most important part of this undertaking is to discover and record as far as possible these unit characters of grapes, thereby aiding to furnish a foundation for grape-breeding. The great problem of plant-breeding in the future will be to correlate the characters known to exist in the plant being improved; we must know what these are before we begin to combine and rearrange them.