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 (V allisneria spiralis], showing vegetative propaga- 

 tion by stolons. Young plants at P l and P 2 . 



