_Cavity and basin._--The cavity, the depression in which the stem is set, offers several marks which greatly enhance the value of a description of any of the pears. The cavity may be _acute_ or _obtuse_; _shallow_, _medium_, or _deep_; _narrow_, _medium_, or _broad_; _smooth_ or _russeted_; _furrowed_, _ribbed_, _angular_, or _uniform_; or it may be _lipped_ as described under stem. The color of the skin within the cavity is sometimes different from that without, and there may be radiating lines, rays, or streaks. The basin, the depression in which the calyx is set, is as important as the cavity in classifying pears and is described by the same terms. The furrows in the basin are sometimes indistinct and are then called _wavy_. The skin around the calyx-lobes may be _wrinkled_, _plaited_, _folded_, or _corrugated_. Rarely, there are fleshy protuberances about the calyx-lobes called _mammiform appendages_. _Calyx-lobes._--The withered calyx-lobes persist in some pears and not in others. They persist in European pears, but are deciduous in the edible-fruited Asiatic species. The calyx-lobes may be _open_, _partly open_, or _closed_ in varieties of the fruits in which they are persistent. In some varieties the segments are separated at the base; in others, united. The lobes may lie flat on the fruit or may stand erect. When upright, if the tips incline inward the lobes are said to be _connivent_; if inclined outward, they are _reflexed_, or _divergent_. The lobes may be _broad_ or _narrow_, with tips _acute_ or _accuminate_. _Characters of the skin._--The skin of all pears offers several most valuable features for classification. Of these characters, color is the most important. Perhaps no character of fruits varies more in accordance with environment than the color, yet the color itself and the way in which it is distributed on the fruit, serve to make this character a fairly safe distinguishing mark for most varieties of pears. The ground-color of pears is the green or yellow-green of chlorophyll, usually with an over-color of tints and shades of yellow or red. The over-color may be laid on in _stripes_, _splashes_, or _streaks_; as a _blush_; may mottle the surface; or may be a single color, in which case the fruit is said to be _self-colored_. In nearly all varieties of colored pears, it is not an uncommon anomaly to find trees under some conditions bearing green fruits. Usually, in pears, the color is laid on solidly; very few varieties have striped or splashed fruits. The skin may be _thick_ or _thin_, _tough_ or _tender_. In a few varieties it is relatively free from the flesh, but with most clings tightly. The surface of the skin is often waxy or oily. This character must not be confused with _waxen_ which refers to the glossy appearance of the skin.