Chapter Iv.--Water Transportation of Plants.

11. Some green buds and leaves float on water . . . . . . . . . 18 12. Fleshy buds drop off and sprout in the mud . . . . . . . . . 20 13. Seeds and fruits as boats and rafts . . . . . . . . . . . . 22 14. Bits of cork around the seeds prevent them from sinking . . 24 15. An air-tight sack buoys up seeds . . . . . . . . . . . . . . 25 16. Fruit of basswood as a sailboat, and a few others as adapted to the water . . . . . . . . . . . . . . . . . . 27