This third form, so common in our hedges (sloe or blackthorn), is very different from the other two. Therefore, unless we interpret by hypothesis what may have happened before all observation, it seems to me impossible to consider the three forms as constituting one and the same species, unless we can show transitions from one to the other in those organs which have not been modified by cultivation, and hitherto this has not been done. At most the fusion of the two first categories can be admitted. The two forms with naturally sweet fruit occur in few countries. These must have tempted cultivators more than _Prunus spinosa_, whose fruit is so sour. It is, therefore, in these that we must seek to find the originals of cultivated plums. For greater clearness I shall speak of them as two species.[1044] +Common Plum+—_Prunus domestica_, Linnæus; _Zwetchen_ in German. Several botanists[1045] have found this variety wild throughout Anatolia, the region to the south of the Caucasus and Northern Persia, in the neighbourhood of Mount Elbruz, for example. I know of no proof for the localities of Kashmir, the country of the Kirghis and of China, which are mentioned in some floras. The species is often doubtful, and it is probably rather _Prunus insititia_; in other cases it is its true and ancient wild character which is uncertain, for the stones have evidently been dispersed from cultivation. Its area does not appear to extend as far as Lebanon, although the plums cultivated at Damascus (damascenes, or damsons) have a reputation which dates from the days of Pliny. It is supposed that this was the species referred to by Dioscorides[1046] under the name of _Syrian coccumelea_, growing at Damascus. Karl Koch relates that the merchants trading on the borders of China told him that the species was common in the forests of the western part of the empire. It is true that the Chinese have cultivated different kinds of plums from time immemorial, but we do not know them well enough to judge of them, and we cannot be sure that they are indigenous. As none of our kinds of plum has been found wild in Japan or in the basin of the river Amur, it is very probable that the species seen in China are different to ours. This appears also to be the result of Bretschneider’s statements.[1047] It is very doubtful if _Prunus domestica_ is indigenous in Europe. In the south, where it is given, it grows chiefly in hedges, near dwellings, with all the appearance of a tree scarcely naturalized, and maintained here and there by the constant bringing of stones from plantations. Authors who have seen the species in the East do not hesitate to say that it is “subspontaneous.” Fraas[1048] affirms that it is not wild in Greece, and this is confirmed as far as Attica is concerned by Heldreich.[1049] Steven[1050] says the same for the Crimea. If this is the case near Asia Minor, it must be the more readily admitted for the rest of Europe.