x] THE FUTURE OF THE GROUP 135 



evolution of fresh-water plants proceeds on its present lines, a 

 greater number may reach the specialised stage of hydrophilous 

 pollination, and some of these may colonise the sea, thus demo- 

 cratising the narrow and exclusive circle of the Marine Angio- 

 sperms^. 



^ In addition to the papers cited in this chapter the following references 

 may be mentioned : 



Ascherson, P. (1870) and (1875}; Chrysler, M. A. (1907); Cunning- 

 ton, H. M. (1912J; Delpino, F. (1870); Delpino, F. and Ascherson, P. 

 (1871); Engler, A. (1879); Hofmeister, W. (1852); Magnus, P. (18702) 

 and (1872); Martens, G. von (1824); Sauvageau, C. (18893) and (i 8912); 

 Solereder, H. (1913); Walsingham, Lord,and Payne-Gallwey,R.(i886); 

 Warming, E. (1871). 



