1903] VEGETATION OF THE BAY OF FUNDY MARSHES 171 
carried up their course instead of down. This wandering of the 
rivers explains many marsh phenomena otherwise very puzzling, 
such as the occasional miniature cliffs in the high marsh, and the 
layers of peat or blue mud (both formed only in presence of 
fresh water away from influence of the tide), exposed by canals, 
or even by the river itself, which thus reaches places formerly 
far removed from it.™ 
When the waters spread over the marsh, they of course drop 
most of their mud, and particularly its coarser parts, on and 
near the banks, thus building the marsh higher there than else- 
where. Hence the drainage of the fresh water, falling on the 
marshes as rain or draining upon them from the upland, is 
obstructed, and it tends to accumulate in the lowest places, viz., 
those farthest from the rivers, and hence near the upland or in 
basins between rivers. This fresh water allows the develop- 
ment of a fresh-water vegetation which initiates the formation of 
true bog, a point of immense importance in the ecology and 
economics of the marsh-vegetation. Again, at the head of tide 
in the rivers, the incoming salt water meets the outgoing fresh 
water and drops its sediment. Thus the rivers are tending 
always to dam themselves up at the contact of salt and fresh 
water, and they would doubtless do so completely were it not for 
the scouring out of the channel by the fresh water when the tide 
is out. The heads of the rivers, too, show another important 
phenomenon, viz., the level of high tide is higher there than at 
their mouths owing to the tendency of tidal rivers to pile up 
their waters on account of the inertia of their rush. It hence 
comes about that the marsh is actually higher at the head of a 
river than at its mouth and the highest part of a marsh is at the 
It explains also the presence of concentric lines of old french dikes at Pros- 
pect Farm on the Aulac, and probably elsewhere, and the fact that the Misseguash is 
not now inthe same position at Pont 4 Buot which it has on the very detailed maps 
of Franquet in 1754. It leads also to the occasional abandonment of pieces of marsh 
too small to be kept diked profitably. 
Mentioned in all works on tidal rivers. I have been told, as a good example of 
it, that the railroad levels show the high-tide level of the Petitcodiac to be higher 
at Salisbury than at Moncton; and Dixon and Trueman mention that at the big 
oxbows on the Tantramar, at “x high and rising tides the water pours back over the 
neck into the river again. 
