Trace the formation of the succulent fruit or hip from the receptacle cup of the flower. Cut through a rose hip, and observe the ripened carpels in the interior.
2. The blackberry.—Similarly examine a blackberry flower ([Fig. 76]). This is still more like a buttercup, but—as in the rose and the pea—the calyx, corolla, and stamens seem to spring from a common base, and not to be inserted separately on the receptacle.
Trace the formation of the compound fruit, and notice that each part is like a little plum or cherry.
3. The cherry.—Similarly examine cherry blossom ([Fig. 77]). The pistil consists of one carpel, and is fixed at the bottom of the receptacle-cup, while the calyx, corolla, and stamens are fixed on the margin of the cup. Trace the origin of each part of the fruit.
Fig. 74.—Apple Blossom. (× ⅓.) Fig. 75.—Wild Rose. (× ⅓.)
4. The apple and pear.—Cut vertically through an apple blossom ([Fig. 74]) or pear blossom (Fig. 78), and notice that the ovary is embedded in the receptacle, and that calyx, corolla, and stamens are fixed on the top of this. Cut across the ovary and see the five divisions (carpels).
The eatable part of the fruit is the swollen receptacle. Compare the hawthorn.