Pawson: Water-Plants as Land-Winners. 227 
matter amongst which they flourish yet more luxuriantly, until 
at length the water is altogether excluded. 
The Norfolk Broads are a network of fens-and shallow meres 
formed along the lower course of several sluggish streams which 
drain an almost level country. They were formerly much deeper 
and more extensive than at present, and the city of Norwich— 
which is now almost in the middle of the county, twenty miles 
from the coast—was a sea-port in the time of the Plantagenets. 
Slowly but surely the marsh-plants are turning these fens into 
dry land. Some of them, although waist-deep, are almost 
grown up by the common Reed; only a narrow water-way 
shows the course of the stream, and the rest of the mere is a 
forest of this, gigantic grass, which rises from the water on 
either side like a wall. In other broads, as Hickling, the smaller 
Bulrush takes the place of the Reed, and entirely overgrows the 
shallow water. Inthe opener and deeper places the S/rafio/es, all 
submerged except its flowering spike, makes a thick subaqueous 
tangle, preparing a place for the Reeds and Rushes, as they in 
their turn will make ready for the plants of more solid ground. 
Where a river enters a lake there is usually a wide stretch of 
Sedge and Flag, which forms a natural filter-bed. This is well 
seen in several of the Westmorland and Cumberland lakes, and 
notably at the head of Derwentwater. Here the stream, which 
in ordinary times flows in a well-cut channel, spreads, when 
in flood, its thick and turbid waters over a square mile of Rushes 
and Reeds before reaching the lake, and leaves behind it a thick 
deposit of mud and wreckage. Thus little by little the marshy 
delta advances and the meadows and pastures steal after it. 
If it were not for these filtering tracts of rank vegetation the 
swollen river would carry its solid freight far into the aoe water 
and the process of lake filling up would be much slower 
The form of these water-plants is nicely adapte oe to this 
purpose. Firmly anchored by their tough, matted or creeping, 
roots in the soft ooze of the bottom, they rear aloft tall, 
upright, slender stems ranged in endless succession like 
a fine screen. They bow to the current but they do not break; 
they take their toll of the water and yield it free passage. 
Their leaves are all narrow and pointing upwards, so as 
t r no unnecessary obstacle. In quieter water floating 
and submerged plants, generally with mesh-like foliage (as 
Myriophyllum, oo Hippuris, Hottonta, Utricularia, 
nacharis, the water Ranunculi, Callitriche, Chara, Nitella, 
and others), are nee busy strainers and mud-gatherers, and 
August 1899: 
4 
