1876. Robert Hogg, the leading pomologist of England, published an artificial system in which new points are considered. The structural characters on which Hogg bases his classification are: 1. The Stamens; 2. The Tube; 3. The Carpels; and 4. The Sepals.
These are all seen when an apple is cut in halves lengthwise from the stem to the calyx. Beginning at the calyx and going inward we find first the calyx segments, which by Hogg and other authors are called the eye, and immediately inside of these segments is a cavity, called the flower-tube or calyx-tube. (By some the word eye is used to denote both the calyx-tube and the segments.) Inserted in this tube is a ring of small, bristle-like organs, which are the dried-up remains of the stamens, and these occupy three different positions in the tube.
Stamens median. a. Stamens marginal.
Tube funnel-shaped. Tube conical.
Core meeting. Core clasping.
6. Cells round.
The tube itself is either conical or funnel-shaped. Further inside just beyond the tube, is the core, the cells of which assume four different forms. Each of these varies in its relation to the axis of the fruit, some extending close to it and forming symmetrical cells, while others are distant from it and are unsymmetrical.
a. Stamens marginal. a. Stamens basal. Tube funnel-shaped. Tube funnel-shaped. Core clasping. Core clasping.
b. Cells elliptical.
1. The Stamens. - Hogg adopts the varying positions of the stamens in the tube as the primary divisions of his system, having found by experience that they are on the whole the most reliable characters where all are more or less changeable. The stamens are (1) marginal, when near the inner end of the tube; (2) median, when near the middle; (3) marginal, when near the outer end. A sharp knife and careful cutting is necessary to determine this accurately. Some varieties have too short a calyx-tube to make three divisions safe, but in general it is a very useful point. Lucas * objects to making the position of the stamens the main character in the classification because it would necessitate cutting the specimens at once which is not always desirable nor practicable. However he admits that the characteristic is in fact a good and constant one, in spite of occasional exceptions and variable varieties.
a. Stamens marginal. a. Stamens median.
Tube conical. Tube conical.
Core meeting. Core clasping.
b. Cells ovate.
Stamens marginal. a. Stamens median.
Tube funnel-shaped. Tube funnel-shaped.
Core clasping. Core meeting.
2. The Tube. - -When conical the outlines proceed from the base of the sepals or segments in a curved line inwards towards the core, forming a cone. These curves are generally inwards, but occasionally they are outwards, as in Fig. 1, which suggested to Hogg the formation of another division, under the name of urn-shaped; but he found it appeared so seldom that no importance need be attached to it. When funnel-shaped the outlines are as when conical, but instead of ending in a point end in a hollow cavity like the stem of a funnel.
Dr. Ed. Lucas, Einleitung in das Studium der Pomologie. 1877, p. 142.
3. The Carpels. - These make up what is popularly called the core. They are generally five, occasionally they are four, or even three, but this is very rare. If split down the middle its walls, or tough membranous lining, will be either round, ovate, obovate, or elliptical. To prevent error in distinguishing between ovate and obovate the observer should hold the apple with the calyx towards him, and the stem pointing outwards.
a. Stamens basal. Core closed. Tube conical. Cells axile. Core clasping.
b. Cells obovate.
In relation to the axis of the apple, they are either axile or abaxile. When the walls extend to the axis, and these characters will be best seen by making a transverse section of the fruit, the cells are symmetrical, and are then said to be axile, whether the core is open or closed. When they are distant from the axis, and the cells are unsym-metrical, they are called abaxile. Further, the walls may be entire, or slit by transverse fissures.
4. The Sepals or Eye. - The sepals or segments of the original calyx of the flowers were uniformly expanded and spreading. After the petals of the flower drop, and fruit develops, the segments persist * and gradually assume various directions, and when it is perfectly matured we find them in four distinct forms: (1) Divergent, when the segments are quite recurved or reflexed, frequently so much as to fall back flat on the fruit in the form of a star; (2) erect convergent, when the segments are never reflexed, but are erect with their margins merely touching and their points divergent;
* In the various varieties of the pure Siberian crab, Pyrus baccata, the segments are deciduous, i.e., fall off as the fruit develops.
Core open. Cells axile.
Core open. Cells abaxile.
Segments erect convergent.
(3) flat convergent, when the segments are flat, closing the eye, but with their margins merely touching and not overlapping each other; (4) connivent, when the segments are all close together, overlapping each other and forming a compact cone. I find the segments are too variable, however, to be depended upon for final judgment in all cases, although they are very useful in many varieties.
Segments flat convergent.
Segments flat convergent.
5. Core. - To the foregoing four divisions by Hogg should be added two points given by Warder. If the outline of the core meets on the inner point or end of the calyx-tube, it is meeting; if some distance below, it is clasping. This is a useful point with many varieties.
Dr. Hogg's key may now be outlined briefly:
Stamens: 1, marginal; 2, median; 3, basal. Tube: 1, conical; 2, funnel-shaped. Cells: 1, axile; 2, abaxile. Cells: 1, round; 2, ovate; 3, obovate; 4, elliptical. Segments: 1, divergent; 2, erect convergent; 3, flat convergent; 4, connivent.
The above provides for 192 classes, each of which if necessary may be further subdivided by form and color into 8 divisions as follows: Form: 1, round or oblate; 2, conical or ovate. Color: 1, pale; 2, colored; 3, striped and russet.
The four color divisions are defned as follows: 1, Pale: a uniform color of yellow or green, notwithstanding it may be faintly tinged on the sun side with orange or pale red. 2, Striped: when the only additional color to that of the ground-color consists of distinct red stripes without any ground-color of red. 3, Colored: when the skin is wholly or partially a decided red, and this may be accompanied with stripes or with some russet. 4, Russet: that in which a russet coat prevails. When a russet coat has a brown or red cheek the fruit is not on that account to be classed in the colored class.
This makes possible a total of 1536 subdivisions. In the smallest groups the season of ripening is given as a further help to direct reference to the appropriate description.