CLASSIFICATION OF THE MONOCOTYLEDONS. 169 



during the flowering period (late in summer) that the surface 

 of the water looks as if flour had been scattered over it. After 

 pollination is effected, the stem of the female flower coils up 

 like a spring, drawing the flower beneath the water where the 

 fruit ripens. 



The cells of these plants show very beautifully the circula- 

 tion of the protoplasm, the movement being very marked and 

 continuing for a long time under the microscope. To see this 

 the whole leaf of Elodea, or a section of that of Vallisneria, 

 may be used. 



