In forming a mental picture of the conditions of life at that early time, it is not necessary to imagine a dreary scene of Arctic sterility. This is not true of the time when the Glacial Age was at its greatest severity. But at the time we are now considering, the glaciers had retreated over a large part of the country, though they still lingered in northern and mountainous regions. Great lakes and majestic rivers were the features of the country. The St. Lawrence was still choked with ice, and the great lakes must have discharged their waters southward.60 The Mississippi, gathering in one mighty stream the drainage of the Central Basin, sped onward to the Gulf, doubtless many times larger than its present representative. The animals then living included several species that have since become extinct. Mastodons and elephants must have been numerous, as their remains are frequently found in loess deposits.61 They have also been found in the gravels of New Jersey, in connection with the rude implements already mentioned. Probably keeping close to the retreating glaciers were such animals as the moose, reindeer, and musk-ox, while the walrus disported itself in the waters off the coast. At any rate those animals now only found in high northern latitudes were living during Glacial times as far south as Kentucky and New Jersey.62 A good deal of interest is connected with the finding of one mastodon’s tooth. It was found in the gravel deposit, about fourteen feet beneath the surface. It must have been washed to the position where found when the great floods from the melting glacier, with their burden of sand and gravel, were rolling down the valley. We can either conclude that the climate was such as to permit the existence of such animals, or that the animal to which it belonged lived in some far away pre-glacial time. But our interest suddenly increases when we learn that, but a few feet away, under exactly similar circumstances, was found the wisdom tooth of a human being. It, too, was rolled, scratched, and polished, and had evidently been swept along by the tumultuous flood. “The same agency that brought the one from the Upper Valley of the Delaware brought the other, and, after long years, they come again to light, and jointly testify that, in that undetermined long ago, the creatures to which they respectively belonged were living together in the valley of the river.”63