



PLATE : 





b of anacharis alsinastrum. 

 p. 166. 



fig. 



Eair or spine 01 anchusa, showing liow 



bard material is deposited. After Mr 



Wenham. p. 166 



Diagram to show direction 



of currents in cells of 



vallisneria. 









a 

 d 



Fig. 249. 





p. 166. 



[To face 



