20 ROYAL SOCIETY OF CANADA 
the long period through which subsidence has been operating and the 
extent to which it has now been carried. 
Ganong (4, 167)) has also shown that the marshes of New 
Brunswick have been and are still being built in a subsiding basin, out 
of red mud brought in from the sea by the rush of the tides, whose 
height is the determining factor in their height. Practically no part 
of their mass has been built from detritus brought down by the rivers. 
During the past summer, Prof. L. W. Bailey of Fredericton, N.B., 
directed my attention to the fact that throughout the entire region of 
the Maritime Provinces, shell heaps which originally must have occupied 
safe positions at some distance from high water mark, are now being 
rapidly eroded, thereby affording proof of the same nature as that 
employed by Mather sixty years ago. 
On the New England coast, at least as far south as Boston, evidence 
of a similar character is abundant. At numerous places, as at York 
and Kittery, the occurrence of tree stumps at levels somewhat below 
low water mark, and their burial by silting, are facts within the know- 
ledge of everyone in the neighbourhood. Furthermore, the erosion of 
exposed areas and the redeposition of the material in sheltered and 
shallow basins, whereby the latter have assumed an entirely new 
character within the recollections of men yet living, are well known 
facts. At Kittery Point this is especially marked. In what is known 
as Pepperrell Cove, and in the adjacent areas protected by islands, the 
silting process has progressed so rapidly that where sixty or seventy- 
five years ago vessels could be brought to the wharf, and where they 
readily found anchorage, it is now impossible to accommodate anything 
but light draught vessels at high tide. It is similarly within the recollec- 
tion of the writer that an arm of Spruce Creek which, in 1865 afforded 
accommodation for boats at all tides, is now inaccessible to row boats 
at low water. In these particular cases the silting has progressed much 
more rapidly than any theoretical rate of subsidence would call for, and 
this may be explained by the circumstance that an abundant growth 
of grass favours the accumulation of silt much more rapidly than would 
otherwise be possible. 
In his annual report for the year 1868, Dr. G. H. Cook 
(1, 543-366) directs attention to abundance of evidence which goes to 
show that a slow subsidence of all the land along the tide waters, not 
only of New Jersey but of the whole eastern coast of the United States, 
has been going on for several hundred years past, and there is further 
evidence that this subsidence is still in progress. This movement is 
one of a series which has occurred on our coast, by which the line of 
water level has been alternately elevated and depressed. The extent of 
