Broadly speaking, the aim has been to make _The Plums of New York_ a record of our present knowledge of cultivated plums. The book has been written for New York but its contents are so general in character that the work applies to the whole country and more or less to the world. The first chapter is a historical account and a botanical classification of plums; the second, a discussion of the present status of plum-growing in America; while the third and fourth are devoted to varieties of plums. The first and last two of these chapters contain the synonymy and bibliography of the species and varieties of plums. In the foot-notes running through the book biographical sketches are given of the persons who have contributed most to plum culture in America; here may be found also matters pertaining to plums not properly included in the text but necessary for its best understanding. Important varieties, so considered from various standpoints, with the bark and the flowers of several species, are illustrated in colors. _The Plums of New York_ is a horticultural and not a botanical work. But in a study of the fruit from a horticultural standpoint one must of necessity consider botanical relationships. It is hoped that in this enforced systematic study of plums, however, something has been added to the botanical knowledge of this fruit. In classifying the varieties and species, to show their characters and relationships, the author has chosen to dispose of the groups in accordance with his own views though the arrangement adopted is, for most part, scarcely more than a modification of existing classifications. Attention must be called to the indefiniteness of species and varieties of plums due chiefly to the extreme responsiveness of the plants to environment. On each side of the specific or varietal types there are wide ranges of variation. Since the relationships between types are often very close it is impossible to avoid some confusion in characters, for outliers of the types cannot but overlap. It might be well said that these outliers are connecting links and that groups so connected should be combined, but this would make specific division of the genus and varietal division of the species almost impossible. The groups must, therefore, be separated along more or less arbitrary lines. But such arbitrary separation does not prevent natural groups, if nature be broadly interpreted. The chief value of the work in hand lies in its discussion of varieties. In the descriptions the aim has been to give as tersely as possible an idea of all of the characters of the plums described. With very few exceptions the technical descriptions of varieties are original and were made by those who have taken active part in the preparation of this book. Nearly all of the varieties having full descriptions grow on the Station grounds but whenever possible specimens of each variety from different localities have been compared with those growing here.