200 GEOLOGICAL SURVEY OF NEW JERSEY. 



elevated parts of the coastal plain, where the morainal debris 

 was heaped, remained above water. Such portions of the 

 former plain region are now represented by Long Island, Block 

 Island, Martha's Vineyard, Nantucket and the lesser islands in 

 the vicinity. Several minor oscillations of level occurred, and 

 finally the land assumed the contour and topography of to-day. 



At the present time, so far as New Jersey and vicinity are 

 concerned, a slow subsidence is recognized as taking place, 

 which amounts to about two feet in a century. This rate of 

 subsidence, while very slow compared with the activity of 

 human events, is probably but little different from that which 

 produced such far-reaching changes in the past. Indeed, its 

 effects have been appreciable within historic time, and we have 

 but to consider the cumulative effects which such a rate of sub- 

 sidence will cause in time in order to appreciate that great 

 changes, topographic and biologic, will be wrought in the 

 future. Surveys have shown that the coast-line has advanced 

 inland hundreds of feet in many localities since the land was 

 first occupied by the whites. Old meadow-turf and tree stumps 

 are to be seen in the ocean-bottom far out beyond the present 

 shore, and what was once upland, capable of cultivation, has 

 become converted into marshes. 



Bearing all these facts in mind, it is certainly pertinent for us 

 to speculate on what the ultimate result may be, provided the 

 present conditions continue. Manifestly the flora which occu- 

 pies the coast region will continue to have its habitat more and 

 more restricted in area and will be driven more and more 

 towards the tension zone, where the struggle for existence with 

 its more highly organized neighbors will be fiercer. The 

 history of evolution in the vegetable kingdom has shown con- 

 clusively that the gymnosperms represent 'a waning type and 

 that the angiosperms have been steadily crowding them out. 

 The former have decreased in numbers and in size, and in any 

 competition for the occupancy of a region at all favorable for 

 the angiosperms these latter are sure to prevail. 



The general trend of events may be foreshadowed from what 

 we have seen has taken place in the past, in the gradual waning 

 of the more primitive gynmnosperm type and the coincident 

 ascension of the more highly organized angiosperm type. The 



