196 TRANSACTIONS OF THE [ApR. 24 



eighty miles, instead of with the near-by coast of NeAV England, 

 not more than twenty miles away.* . 



We therefore have to consider the fact of a characteristic 

 flora, whose principal habitat is on the mainland southward, 

 extending from New Jersey on to Staten Island, thence on to 

 Long Island and the islands to the eastward, a,nd then reap- 

 ])earing on the mainland again in a limited area in southeastern 

 New England. We have further to consider the significant fact 

 that while in its northward extension it is a coast flora entirely, 

 southward it exists not only near the coast, but over an area 

 many miles inland. This significance will be better understood 

 and appreciated when the geology of the region comes to be 

 discussed. Considering the flora alone we might readily 

 imagine a continuous strip of mainland to exist through the 

 region now occupied by it, while Connecticut, with its little 

 adjacent areas of New York and New Jersey would represent 

 a more or less isolated island. 



What, then is the most reasonable explanation of these 

 botanical facts which we have established? Suppose we see 

 what the geology of the region can tell us. 



PART II. 



Daring Cretaceous and Tertiary times a series of fresh water 

 or estuary and marine deposits (clays, sands, gravels and 

 marls) were laid down along the eastern borders of the North 

 American continent. About the close of the Miocene, or the 

 beginning of the Pliocene period, an era of elevation began 

 which finally raised them hundreds, in places thousands of feet, 

 above their present level, forming a vast coastal plain, which 

 extended over the entire area where we now find them, and for 

 a considerable distance eastward, into what is now part of the 



* " Catalogue of Plants Growing Without Cultivation in the County of Nan- 

 tucket, Mass." 



■■ The Pine barrens, although farther south, itro of similar structure, and 

 Nantucket, as regards its flora, seems like a piece of New Jersey moved up the 

 coast for the convenience of northern amateurs in botany, who cannot get away 

 from business long enough to go collecting in that State . . . Trees 

 are lacking excei)t in stunted form, and there are few of those, yet the tradition 

 is that the island was well wooded when the first settlers came in ifiso 

 Some wood plants probably died out soon after the trees that sheltered them 

 were gone; but even now Nantucket, though treeless, is not a flowerless isle 



The island flora interests all botanists from its peculiarity . . 

 they are surprised at the occurrence of species not to be expected in. this 

 latitude . . • some belong to more northern localities, but those are 

 far hiss numerous than the southern plants, some of which have never been 

 found elsewhere in New England." 



