This illustration shows stages in the germination of the gametospore of Lepidium, sectional view: A, micropylar end of embryo sac, showing the enlarging gametospore provided with cell wall and attached to wall of sac. B, later growth-s, suspensor; e, embryo cell; en, endosperm cells. C, pro-embryo after first division of embryo cell. D, further divisions of embryo cell, showing formation of an epidermis and a central stem region. E, later growth, two growing regions, the cotyledons, appearing on the sides of the stem. F, plant or embryo, consisting of two cotyledons, c; stem, st, which terminates in the root, r; the endosperm cells, en, are ebing absorbed by the enlarging embryo; s, suspensor.

Lepidium

This illustration shows stages in the germination of the gametospore of Lepidium, sectional view: A,…