2 BULLETIN 179, U. S. DEPARTMENT OF AGRICULTURE. 
for pasture have afforded favorable conditions for a considerable 
increase in the number of individuals. In other localities the 
abandonment of cultivated fields has afforded very similar oppor- 
tunities, with a like result. In still other regions, areas are being 
placed under cultivation, and by this or other means the number of 
individuals is being decreased. The horticultural literature of the | 
Northwest contains so many references to the destruction of plum 
thickets that it is probable that in that region at least the genus is 
less abundant than when settlement began. The actual number of © 
species may also soon be lessened, since a few of them are extremely | 
local, and at least one of the latter, Prunus alleghaniensis, is known 
recently to have disappeared in some of the localities where it for- 
merly existed. 
VARIATION AND ADAPTABILITY. 
There is great variation within the species in the size and quality 
of the fruit and apparently in the productiveness of individual trees. | 
Any systematic attempt to improve the native plums should begin | 
with a study of the species in the field in at least a portion of the — 
range of each. In this way forms may be secured which so far | 
surpass the usual quality of the species that they could otherwise be — 
obtained only after many years of selection in the orchard. Several — 
of the American species bear fruit that is distinctive in character — 
and that possesses qualities of value. Their hardiness and adapta- — 
bility to the regions in which they are native render some of them — 
indispensable if those regions in which the Old World species are not 
successfully grown are to be supplied with home-grown fruit. Some | 
of these may eventually be so improved that they will even find a 
place in localities where they will compete for dessert purposes with, 
varieties originating from Old World species. 
EARLY HISTORY OF AMERICAN PLUMS. 
The history of American plums, so far as Europeans are concerned, 
probably begins with the visit of John de Verrazano, a Florentine | 
voyager, who sailed from the vicinity of Madeira on January 17, 1524, — 
under orders from the French king, FrancisI. He reached America — 
at about latitude 34° north, and proceeded northward along the coast | 
to latitude 50°, when he departed for France. The explorer’s | 
account of his voyage is dated at Dieppe, July 8, 1524, and in his | 
enumeration of American products observed at about 41° north, or | 
the latitude of southern New York, he states (29, p. 362): ‘‘We 
found Pomi appii, damson trees, and nut trees.’”’ The voyagers | 
apparently nowhere went far inland, and the ‘‘damson, trees”’ were — 
with little doubt Prunus maritima, since this is the only species in 
1 Reference is made by number to “Literature cited,” p. 73. 
