Srcrion IV., 1907. [13] Trans. R. 8. C. 
III.—A Contribution to our Knowledge of the Origin and Development 
of Certain Marsh Lands on the Coast of New England. 
By D. P. PENHALLOW, D.Sc. 
McDonald Professor of Botany, McGill University. 
(Read May 15, 1907.) 
At numerous points along the Atlantic coast, the salt water makes 
inland at high tide through a breach in the protecting barrier wall, and, 
flooding all the low lying lands in the neighbourhood, establishes 
conditions which exclude all but halophytic types of vegetation, and 
thereby favours the almost exclusive development of the salt marsh 
grasses of the genus Spartina. The process by which salt marshes were 
formed and are yet forming, involves features of the greatest interest, 
the first interpretation of which was given by Mather (5, 17) in 1843. 
More recently his account has been adopted by Shaler (6) without any 
essential modifications though in a much elaborated form, and his paper 
on the tidal marshes of the Atlantic Coast is at present standard 
authority. 
Recent studies, however, have shown that the account referred to 
fails to recognize some important features which it is the purpose of the 
present paper to discuss in order to bring them into their proper 
relations with the sequence in development as set forth by Shaler, and 
to ascertain the possible connection between salt water marshes and 
fresh water bogs with respect to origin and mode of development. 
For the purpose of our present studies it will be sufficient to have 
general reference to those marsh lands which everywhere lie along the 
coast line from Cape Ann to Portland, and constitute both familiar and 
characteristic features of the landscape, for those who are accustomed 
to travel on the eastern division of the Boston and Maine Railway. 
Particularly noteworthy, because brought under the direct observation 
of the traveller, are the extensive marshes about the head waters of 
Plummer’s River between Ipswich and Newburyport, and again at 
Hampton where, in both cases, the characteristic features of such 
marshes may be seen from one point of view and under very favourable 
circumstances. 
From North Hampton northward, the coast line becomes somewhat 
bolder with the result that the marshes diminish in size but develop 
with greater frequency, so that in the section of coast lying north of 
the Piscataqua River and extending thence as far as the Nubble at York, 
