To this point I feel that I have been handling facts only, and deducing from them only logical inferences; but now looms up the natural and ever-interesting question, Who were these people? The origin of any race is a difficult problem to solve, but none can compare with these misty vestiges of prehistoric humanity. It seems to me but one inference is permissible: they who fashioned these rude argillite implements were the descendants of palæolithic man, and his superior in so far as a knowledge of the bow and arrow and rude pottery indicates. Beyond this, perhaps, we can not safely venture. Prof. Haynes has recently observed, “The palæolithic man of the river gravels at Trenton and his argillite-using posterity the writer believes to be completely extinct.” While this at present seems to be the generally accepted conclusion, there is a phase of the subject that merits consideration. May not this “argillite-using” man have been a blood-relation of existing Eskimos? To accept the view of Prof. Haynes that “argillite” man became extinct infers an interval of indefinite length, when man did not exist on our central Atlantic seaboard; but if we may judge from the abundant traces of man that have been left and of the relation as to position that these three general forms—palæolithic, later argillite, and Indian—bear to each other, it would appear that, in the valley of the Delaware, at least, man has not for a day ceased to occupy the land since the first of his kind stood upon the shores of that beautiful river. By referring these intermediate people to the existing Eskimos, I would not be understood as maintaining that these boreal people were directly descended from the argillite-using folk of the Delaware Valley, but that both were derived from palæolithic man; in other words, that with the disappearance of glacial conditions in the Delaware Valley, and the retirement northward of the continental ice-sheet, if such there were, the people of that distant day followed in its tracks, and lived the same life their ancestors had lived when northern New Jersey was as bleak as is Greenland to-day; but that not all of this strange people were so enamored of an arctic life, and that many remained and, with the gradual amelioration of the climate, their descendants changed in their habits so far as to meet the requirements of a temperate climate. This explanation, it seems to me, best accords with known facts.