42% ROYAL SOCIETY OF CANADA 
that the entire structure superimposed upon the sphagnum, must have 
formed within a maximum period of four hundred and twenty years 
as indicated by the following analysis :— 
Period for salt marsh turf, 75 years, maximum...... 100 years 
First peat zone with white pine, seven inches...... 70 years 
Second peat zone with small white pine, 20 inches.... 200 years 
Cassandra zone, 4-5 inches, maximum.............. 50 years 
Lotal. up at 2000 re er RE rude OMe eames 
Sphagnum growth of an indefinite period. 
In connection with this analysis, reference should be made to the 
previous statement that the large pine trees are estimated to have 
attained an age of seventy to one hundred years. The rate of growth 
for that peat zone, in accordance with Shaler’s estimate, would give a 
period of seventy years which is in practical agreement with the estimate 
derived from the trees. 
It is impossible to assert that this marsh structure was formed 
within the time limit indicated, though there is a very strong element 
of probability that the estimate is not too small; but, however, this may 
he, the facts do seem to indicate with very great force, that the marsh 
is of very recent origin, a conclusion which also seems in accord with 
the present history of similar bogs in the neighbourhood, bogs which 
at any time may become converted into salt marshes by a series of 
changes similar to those recorded for the Brave-Boat Harbor marsh. 
LITERATURE. 
Cook, G. H. (1) Geology of New Jersey, 1868, pp. 343-366. 
(2) Geology of New Jersey, 1885, pp. 61-70. 
Dawson, Sir J. WILLIAM. (3) Acadian Geology, ed. 3, London, 1878. 
GANONG, W. F. (4) The Vegetation of the Bay of Fundy Salt and Dyked 
Marshes; an Ecological Study. Bot. Gaz., XXXVI, 1903, pp. 161-186; 
280-302; 349-367; 429-455. 
MATHER, W. W. (5) Geology of New York, Part I, comprising the Geology 
of the First District. 1843, pp. 19-23, and 169 et seq. 
SHALER, N. S. (6) Beaches and Tidal Marshes of the Atlantic Coast. Nat. 
Geog. Soc. Monogr., Vol. I, 1895, pp. 137-168. 
(7) The Fresh Water Morasses of the United States. Tenth 
Ann. Rept. U. S. Geol. Surv., 1890. 
SPENCER, J. W. (8) The Submarine Great Cafion of the Hudson River. 
Amer. Jn’l Sci, XIX, 1905; pp. 1-5. 
(9) Submarine Valleys off the American Coast and in the North 
Atlantic. Bull. Geol. Soc. of Amer., XIV, 1903; pp. 207-226. 
