VI] 



MARSH AND AQUATIC ASSOCIATIONS 



155 



THE VEGETATION OF QUICKLY FLOWING STREAMS 



("The hydrophyte formation round springs and streamlets." 



Ostenfeld, 1908 : 943.) 



The streams of the Pennine slopes are characterized by their 

 quick current and their shallowness. A result of their quick 

 current is that the water is well aerated; and this factor is 



