_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. The varieties are arranged alphabetically throughout, though, were present knowledge exact enough, it would be far better to arrange them in natural groups. Such a classification is probably possible, but it remains for future workers to search out the relationships which the structures and qualities of plant and fruit indicate and to group the varieties naturally rather than alphabetically. Wherever possible in this work, however, the relationships of varieties have been indicated as fully as knowledge permits, thus making a start toward natural classification.