Page:The Oak.djvu/143

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125
INFLORESCENCE AND FLOWERS—FRUIT AND SEED.

tudinally this cupule will be seen to consist of a ring of tissue, arising from beneath the ovary, and with its margin notched into scales. As the ovule enlarges the minute scales become more numerous, new ones arising at the inner margin of the up-growing cupule.

The Oak (Marshall Ward) Fig 33.jpg
Fig. 33.—A group of female flowers
(slightly magnified). Each has a
spreading stigma above and the
commencing cupule below, and arises
from the axil of a pointed bract.
(Th. Hartig.)

A transverse section across the female flower at a slightly later period shows that the inferior ovary is divided into three chambers (loculi), each corresponding to one of the lobes of the stigma, and each containing two ovules (Fig. 34). These ovules are inserted at the upper part of the inner angle of the chamber, and thus hang down in pairs. A curious point arises here. It seems that at the period when the female flower has just opened, but has not yet received any pollen on its stigma, neither the ovules nor the chambers are as yet formed, and the segments of the perigone spring from the lower portion of the flower, and this condition is not altered until pollination occurs; then the tissue below the stigma becomes the three-chambered ovary sunk in the perigone.

The pollination takes place in May-June, and ferti-