ACCORDING to paleontological data, the genus Pyrus (the pear proper) is of Tertiary or, possibly, even more ancient origin. Tertiary remains (leaves) have so far been found only in a few localities of western Europe and the Caucasus. In western Europe-in Miocene deposits at the famed site of Tertiary remains, the village of Parschlug in Steyrmark, Austria-Unger found and described the fossil species, Pyrus theobrorma. In the Caucasus, according to Palibin, P. theobroma is found in eastern Georgia in the Kakhetia Mountains in Middle and Lower-Middle Sarmatian deposits, together with representatives of a mixed flora including a considerable number of evergreens, which attests a subtropical or, at least, a warm climate. P. comminunis L. is found in eastern Georgia in Upper Pliocene deposits in the Akchagyl horizon and in Azerbaidzhan in the Apsheron horizon. In all cases these fossil remains are found among representatives of a warm, temperate climate, together with numerous species identical to present-day forms. Post-glacial remains of the pear' (fruits) are known in lacustrine deposits in Switzerland and Italy. In contrast to the closely related genera, Malus and Crataegus, 'which belong to the so-called arctic-Tertiary flora and have, like other members of this flora, representatives both in Asia and North America, the genus Pyrus has no fossil occurrences in North America. This specificity in the location of fossil remains of Pyrus and the peculiarities of the present geographical distribution of the genus indicate that it originated at a later date than the other genera mentioned and in a different geographical region.