This tree is an interesting hybrid between _P. communis_ and the whitebeam, _P. aria_. It was first noticed at Bollweiler, Alsace, and was first mentioned by J. Bauhin in 1619. It is propagated by grafts as few of the seeds are fertile and these do not come true to name. It bears fruit very sparingly, none being produced in some seasons. Besides the species that have been named there are several other occidental pears named by European botanists which may be looked for in botanic gardens. Some of these might have value for work in hybridization but it is doubtful. Of these, _P. heterophylla_ Regel and Schmalhausen (_Act. Hort. Petropol_ =5=:pt. ii, 581. 1878) is a small thorny tree from the mountain valleys of Turkestan. _P. amygdaliformis_ Villars (_Cat. Meth. Jardin Strasbourg_ 323. 1807) is a spiny shrub or small tree, bearing small worthless fruits; a native of arid soils in the regions of olives in southern Europe. _P. salicifolia_ Pallas (_Itin._ =3=:734. 1776) is a small spiny tree from the Crimea, Caucasas, and Armenia; the fruit has little or no value. _P. syriaca_ Boissier (_Diag. Nov. Pl. Orient_ =10=:1. 1849) is a thorny, shrubby tree from Syria, Asia Minor, and Kurdistan. A review of botanical literature shows several other names of doubtful species of Pyrus which seem more likely to be hybrids or abnormal escapes from orchards. There are, also, many names which seem to be synonyms. Material and literature at hand do not enable the author to make certain of these, even if any sufficiently worthy purpose could be served in a pomological text. ORIENTAL PEARS The oriental pears have been brought to America in comparatively recent years, chiefly as ornamentals and for blight-resistant stocks; but hybrids of at least one species of this group, _P. serotina_, with the common pear have given many valuable orchard varieties. The Chinese and Japanese cultivate several species for their fruits. These pears constitute a group quite distinct in aspect of tree and fruit, but no characters not in occidental species are found in all species of the oriental group. The most constant differences, besides region of origin, are found in the leaves and the calyx. The leaves in most species are markedly acuminate and their margins are sharp-serrate or setose-serrate. The calyx falls from the fruit in the species now cultivated for food, but does not in two species promising for stocks. [Illustration: _PYRUS SEROTINA_] =4.= =PYRUS SEROTINA= Rehder =1.= Rehder _Proc. Amer. Acad. Arts & Sci._ =50=:213. 1915.