THE PROBLEM OF SEX IN PLANTS 



349 



FIG. 256. Bryophyllum crenatum. A leaf which has given rise to three 

 plantlets along the margin of the blade. 



FIG. 257. Eel-grass (Vallisneria spiralis), showing vegetative propaga- 

 tion by stolons. Young plants at P 1 and P*. 



