564 INTER-GLACIAL AMERICAN NAN. 



in glacial times on the Atlantic coast of North America." Such 

 then being the present state of this important inquiry, a review of 

 the evidence thus far adduced cannot fail to be of interest. 



The Report of Dr. Abbott is produced as an embodiment of the 

 results of " investigations in the valley of the Delaware, made with 

 reference to the occurrence of supposed palaeolithic implements in 

 the gravel beds facing that stream, based upon a series of careful 

 examinations of the deposits in qiiestion, made at different points, 

 together with a study of the surface soils, so far as these, of them- 

 selves and by their contained relics, bear upon the question of the 

 origin and character of the specimens of stone implements taken 

 from the underlying gravels." Keeping carefully in view the mis- 

 leading traces of comparatively modern Indian remains in deposits 

 geologically ancient, he remarks : " The chance occurrence of single 

 specimens of the ordinary forms of Indian relics, at depths somewhat 

 greater than they have usually reached, even, in constantly cultivated 

 soils, induced me, several years since, to carefully examine the under- 

 lying gravels, to determine if the common surface-found stone imple- 

 ments of Indian oiigin were ever found therein, except in such 

 manner as might easily be explained, as in the case of deep burials 

 by the uprooting of large trees, whereby an implement lying on the 

 surface, or immediately below it, might fall into the gravel beneath, 

 and subsequently become buried several feet in depth ; and lastly, by 

 the action of water, as where a stream, swollen by spring freshets, 

 cuts for itself a new channel, and carrying away a large body of 

 earth, leaves its larger pebbles, and possibly stone implements of late 

 origin, upon the gravel of the new bed of the stream." 



But while thus recognizing the intrusion of relics of modern Indian 

 workmanship at considerable depths in ancient gravels. Dr. Abbott 

 claims to have discovered, independent of those, and readily distin- 

 guishable from them, thoiigh in the same underlying gravels, certain 

 rudely shaped specimens of chipped stone, which have all the charac- 

 teristics of the stone implements of palaeolithic times. These are 

 classified by him into a primitive form, to which he has given the 

 name of "turtle -back" celt, with modifications of the same, and 

 others approximating to the more familiar forms of the hatchet, the 

 spear, and the scraper ; while the deposit in which they occur is 

 largely made up of ordinary smooth water-worn pebbles, varying in 

 size from half an inch in diameter to boulders estimated to weigh 



