Page:Popular Science Monthly Volume 5.djvu/154

From Wikisource
Jump to navigation Jump to search
This page has been validated.
142
THE POPULAR SCIENCE MONTHLY.

If the reader will take an apple—a rotten one is best—and cut it through from flower-scar to stem, he will find a core of five carpels, and about midway between the core and the rind he will see a green, fibrous line (Fig. 9). If he will look now at the flower, he will find the cup or calyx of five sepals, the corolla of five petals, the stamens many (a number of whorls), and the pistils five (one whorl). We have shown that these floral organs are simply transformed leaves, and we shall now see that the apple itself is merely these leaf-whorls still further transformed.

Let us cut the apple through around the equator and compare our section (Fig. 10) with the longitudinal one (Fig. 9). Looking at the flower-scar, we see the remnants of the sepals, d, d, d. Within and alternating with these are remnants of the petals, c, c. Still farther within is a little shred of a pistil, b. This shred can be traced down into the core, a. The other parts of the flower lose themselves in the fleshy fruit.

If we look now at the other section (Fig. 10), we shall see, on that fibrous line, ten greenish points, five opposite to the carpels and five alternating with them. Five other little points appear near the tips of the carpels and in line with them. Now, this fibrous line, and the points on it and within it, must bear some relation to the plan of the flower. And, as the stamens are a multiple of five, the points must have some relation to the staminate whorls. The core, as we see (Fig. 9), is continuous with the pistil. It is simply the base of the

Fig. 10. Fig. 11.
Cross-Section of Apple, showing the Carpels and Fibrous Points. Section of the Kittanning Apple, a, cavity which takes the place of the carpels; f, fibrous line.

pistillate whorl. The part of the fruit between the core and the dotted line represents the thickened and coalesced whorls of stamens and petals.[1] The fruit between this dotted line and the fibrous line represents the thickened petals. The fibrous line represents the union of

  1. This line is not found in the fruit. It is ideal.