Day 5, 6
Day 5, 6. This is what the box of seeds will look like on Day 5-6.
Figure 12. Beginning germination of bean seeds. Red kidney bean seeds beginning to germinate. Credit: M.E. Conley
If you remove one of the beans from the box, you will see the primary lateral roots (arrow) forming off the radicle. The cotyledons continue to swell. Inside the seed, the epicotyl (not visible) is greening up and the unifoliate leaves are more defined but still within the seed coat.
Figure 13. Lateral roots of a red kidney bean seed. Lateral roots (arrow) beginning to form off the radicle. Credit: E.T. Paparozzi
Figure 14. Stained cross-section of the radicle. Cross-section (transverse) through the radicle showing the origination of a lateral root (arrow) from the radicle. Stained with toluidine blue O. Magnified 36 times. Credit: E.T. Paparozzi
If you gently peel away the seed coat and tease apart the cotyledons, you will find the unifoliate leaves (arrow) beginning to green up.
Figure 15. Two unifoliate leaves inside the bean seed. Inside the seed, surrounded by one of the cotyledons, a first view of the two unifoliate leaves (arrow) greening up and expanding. Magnified 12 times. Credit: E.T. Paparozzi