DOCHNAHL'S CLASSIFICATION.
SECTION I.—PLEUROIDEA.—Angular or Ribbed.
Having sharp or flat ribs, which extend over the length of the fruit and are most prominent around the eye, where they are most generally situated.
CLASS I.—MALA CYDONARIA—Quince-shaped.
ORDER I.—CALVILLES.
1. They have large heart-shaped cells, open towards the axis, or often entirely torn; the cells extend very often from the stalk even to the tube of the calyx.
2. They diminish from about the middle of the fruit, or a little above it, towards the eye.
3. They are regular, and provided generally with fine ribs, which do not disfigure the fruit.
4. On the tree, the fruit is covered with bloom.