INTRODUCTION 13 



deal of morainic material around Beacon Hill, makes this forma- 

 tion the oldest in New Jersey, either on the coastal plain or in the 

 glaciated regions northward, that could have been continuously 

 covered with vegetation. This, it would seem, is why the Beacon 

 Hill formation is the controlling factor in the origin and present 

 distribution of the pine-barrens. The area of the pine-barrens 

 (see pi. 3) is not exactly coextenive with Beacon Hill (see pi. 4), 

 but the differences are so slight that recent and local erosion of 

 the formation would account for the failure of the two regions to 

 superimpose, as it were. 



26. In other words, the New Jersey pine-barrens exist exclu- 

 sively on this Beacon Hill formation, an area isolated by geological 

 processes, and maintaining a relict or climax flora, the antiquity 

 of which greatly antedates any of the rest of our vegetation here- 

 abouts, so far as permanency of position and phytogeographical 

 isolation are concerned. This undoubtedly accounts for the com- 

 position of the flora, and it is interesting to note that zoologists 

 have found this same apparent isolation, the same endemism 

 noted above. The sphagnum frog, Rana virgatipes, described by 

 Cope and collected only thrice since, is unknown outside of this 

 region,* and the late John B. Smith in his work on the insects of 

 New Jersey has figured the "entomological pine-barrens" as very 

 nearly coinciding with the floral pine-barrens.j 



Effects of the Geologic Changes Described A bove 



27. In the light of this historical outline it should be easy to 

 trace the development of the vegetation of the coastal plain from 

 the Miocene uplift until the present. Ancestrally it must have 

 consisted of purely American plants, and many of these, in all 

 probability, were of southern extraction. J Of the 565 species 

 found growing here, not counting weeds, 386 are listed as truly 

 pine-barren. This does not mean that they are found nowhere 

 else, but that so far as New Jersey is concerned these plants find 

 their greatest development in the pine-barrens. There is a small 

 element among them practically unknown outside of the pine- 



* Fowler, H. W. Proc. Acad. Nat. Sci. Philadelphia 57: 662-664. 1905. 

 f Ann. Rept. New Jersey State Mus. 1909. Map (frontispiece) 1910. 

 X Over 180 species of the present flora of the pine-barrens range from New Jersey to 

 Virginia and Florida. 



