470 HARSHBERGER— INFLUENCE OF SEA WATER [April 22, 



7. Water from seaward end of marsh island in Shark River. 

 Sp. gr. 1. 017. With Spartiiia stricta niaritiuia. 



8. Water submerging J uncus Gcrardi. Sp. gr. 1.016. 



9. Water covering Spartiiia patens. Sp. gr. 1.017. 



12. W^ater in large slue along Fifth Avenue, Belmar. Sp. gr. 

 1.016. 



13. Water from bay at Casino Landing, where a rise of eighteen 

 inches was noted after the inlet closed. Sp. gr. 1.0175. 



These several readings show the condition of salinity when the 

 inlet through which the tidal salt water enters Shark River is closed 

 and the salt water thus inclosed is diluted by rain and river water 

 until the river shows a perceptible rise of eighteen inches above the 

 level of normal high tide. In such rivers the salt marsh vegetation 

 for considerable periods of time is exposed to fresh water, which 

 w^ould ultimately control, if the inlet would remain permanently 

 closed. But when the inlet is reopened the original conditions of 

 salinity are restored by the tidal flow of sea water in and out of the 

 landlocked bay. This is an interesting corroboration of the recent 

 work of D. W. Johnson,^ who believes that the indications of appar- 

 ent subsidence are due to fluctuations in the tidal level due to a 

 change in the configuration of the coast. During the closure of 

 Shark River there was a rise of water level in the river which might 

 account for the rise in the height of the salt marsh layers. After 

 the causal influences had been obliterated, an examination of the 

 layers of salt marsh soil would indicate, according to the older views, 

 a total submergence of the coast line equal to the depth of newly 

 formed marsh peat. 



The observations on the salinity of the water at the western end 

 of Newberry (Stockton) Lake, an arm of Manasquan River, are 

 of interest as displaying the edaphic conditions which control the 

 distribution of Typha angustifolia. The size of this plant is also 

 directly conditioned by the amount of salinity as measurements later 

 to be presented will show. However, if we begin near the outlet 



^Johnson, D. W., "The Supposed Recent Subsidence of the Massa- 

 chusetts and New Jersey Coasts," Science, N. S., XXXII., 721-723; Bartlett, 

 H. H., " Botanical Evidence of Coastal Subsidence," Science, N. S., 

 XXXIII., 29^31 ; Johnson, D. W., Science, XXXIII, 300-302. 



