PROPAGATION OF WILD-DUCK FOODS. 



15 



Fig. 9. — Potamogeton natans. B394M 



Fig. 10. — Potamogeton lucens. 



Fig. 11. — Potamogeton heterophyllus. Fig. 12. — Potamogeton lonchites. B397M 



Figs. 9—12. — Wide-ranging species of pondweeds. (From Morong.) 



