The first of these species, from which the white and black cherries are developed, is wild in Asia; in the forest of Ghilan (north of Persia), in the Russian provinces to the south of the Caucasus and in Armenia;[1012] in Europe in the south of Russia proper, and generally from the south of Sweden to the mountainous parts of Greece, Italy, and Spain.[1013] It even exists in Algeria.[1014] As we leave the district to the south of the Caspian and Black Seas, the bird-cherry becomes less common, less natural, and determined more perhaps by the birds which seek its fruit and carry the seeds from place to place.[1015] It cannot be doubted that it was thus naturalized, from cultivation, in the north of India,[1016] in many of the plains of the south of Europe, in Madeira,[1017] and here and there in the United States;[1018] but it is probable that in the greater part of Europe this took place in prehistoric times, seeing that the agency of birds was employed before the first migrations of nations, perhaps before there were men in Europe. Its area must have extended in this region as the glaciers diminished. The common names in ancient languages have been the subject of a learned article by Adolphe Pictet,[1019] but nothing relative to the origin of the species can be deduced from them; and besides, the different species and varieties have often been confused in popular nomenclature. It is far more important to know whether archæology can tell us anything about the presence of the bird-cherry in Europe in prehistoric times. Heer gives an illustration of the stones of _Prunus avium_, in his paper on the lake-dwellings of Western Switzerland.[1020] From what he was kind enough to write to me, April 14, 1881, these stones were found in the peat formed above the ancient deposits of the age of stone. De Mortillet[1021] found similar cherry-stones in the lake-dwellings of Bourget belonging to an epoch not very remote, more recent than the stone age. Dr. Gross sent me some from the locality, also comparatively recent, of Corcelette on Lake Neuchâtel, and Strobel and Pigorini discovered some in the “terra-mare” of Parma.[1022] All these are settlements posterior to the stone age, and perhaps belonging to historic time. If no more ancient stones of this species are found in Europe, it will seem probable that naturalization took place after the Aryan migrations. +Sour Cherry+—_Prunus cerasus_, Linnæus; _Cerasus vulgaris_, Miller; _Baumweichsel_, _Sauerkirschen_, in German. The _Montmorency_ and _griotte_ cherries, and several other kinds known to horticulturists, are derived from this species.[1023]