INTER-GLACIAL AMERICAN MAN. 573 



But the source of the later local changes, thus assumed to pertain 

 to an inter-glacial epoch, has still to be determined ; and with it the 

 geological age of the drift gravel in its present condition. Professor 

 Prestwich and others who discussed the age of the tool-bearing strata 

 of Northern Europe, urged that their positions in the valleys show 

 them to be more recent than the glaciations of the districts in which 

 they occur ; and the character of the drift gravel of the Delaware 

 River Valley, seems still more open to a similar characterization. In 

 the gravel of Long Branch, which according to Prof. Smock, the 

 Assistant State Geologist, is of the same age as that at Trenton, 

 rolled fragments of reindeer horns occasionally occur, and two skulls 

 of the walrus have been found. Prof. Pumpelly has also visited 

 the principal localities in which Dr. Abbott has carried on his 

 researches ; and both he and Prof. Shaler remark on the absence of 

 ice scratches on the pebbles and boulders forming the deposit ; and 

 they apparently arrive" at the same conclusion, that it is originally of 

 glacial origin, but that its materials have been subsequently modified 

 by the action of water, and so re-arranged with more or less of 

 stratification. Dr. Abbott accordingly reverts to those deductions, 

 communicated to him after the original draft of his Report had been 

 written, and adds this comment: "Inasmuch as such subsequent 

 action may have occurred long after the final deposition of the gravel 

 as true glacial drift, the antiquity of the contained stone implements 

 is proportionately lessened, and may be wholly unconnected with the 

 glacial period, although the latest possible date that can be assigned 

 to the deposition of the gravel in its present condition gives an 

 antiquity to the implements found therein far gi'eater than can be 

 asserted of any previously found traces of man in North America, 

 other than the discoveries of Prof. Whitney in California." 



The subject is one which will not fail to receive ample consi- 

 deration from those best qualified to test the full bearings alike of 

 the archaeological and the geological evidence. The researches have 

 thus far been carried on with funds appropriated for the purpose 

 by the Board of Trustees of the Peabody Museum of American 

 Archseology and Ethnology ; and the fruits of Dr. Abbott's labours 

 are justly referred to in their annual report as probably the most 

 important result attained in American archaeology during the past 

 year. 



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