All, howsoever interested in pomology, are dependent upon descriptions of fruits. A well-made description of a fruit, to one mentally equipped to interpret it, is second only, in the study of pomology, to having the fruit itself. With but few exceptions the descriptions of the major varieties are made first hand from cherries growing on the Station grounds, though in many cases fruits from different localities have been compared with those home-grown. Since there are fewer varieties of cherries than of plums, it has been possible to describe and illustrate a greater proportion of the sorts under cultivation than in the book on plums, yet a selection has had to be made of the worthiest of the many kinds. The choice of sorts for full descriptions and color-plates has been determined: (1) By the present value of the variety; (2) the probable value if the variety be a novelty; (3) by the value of the data to the cherry breeder; (4) because of historical value--to show what the trend of cherry evolution has been; (5) to show the relationships of species and varieties. The varieties not illustrated nor fully described are divided into two further groups in accordance with the same considerations. In botanical nomenclature the code adopted by the International Botanical Congress, held at Vienna in 1905, has been used. In the use of horticultural names we have followed somewhat closely the rules of the American Pomological Society, though in many cases strict observance of these rules, poor at best, would have added to rather than lessened the confusion in horticultural nomenclature and, therefore, they have been honored in the breach rather than in the observance. The references given are those that have been of use in ascertaining the history, the economic status, or the description of the variety that follows--no more, no fewer. These constitute a very small proportion of the references that have been read--a tremendous task involving two or three years' work for several persons. So, too, it has been a herculean task to search out the synonyms of cherries. French, German, English and American books on pomology overflow with such synonyms and all in a state of "confusion worse confounded." An enormous amount of work has been done in trying to bring order out of this confusion. Many of the synonyms of varieties have been given in times past because of adaptations to local environment. Such naming of ecologic forms is not an unmixed evil, since it draws attention to variable varieties and characters which otherwise might be overlooked.