And how was that great lowland swept away? Who can tell? Probably by no violent convulsion. Slow upheavals, slow depressions, there may have been—indeed must have been—as the sunken fir-forests of Brancaster, and the raised beach of Hunstanton, on the extreme north-east corner of the Wash, testify to this day. But the main agent of destruction has been, doubtless, that same ever-gnawing sea-wash which devours still the soft strata of the whole east coast of England, as far as Flamborough Head; and that great scavenger, the tide-wave, which sweeps the fallen rubbish out to sea twice in every twenty-four hours. Wave and tide by sea, rain and river by land; these are God’s mighty mills in which He makes the old world new. And as Longfellow says of moral things, so may we of physical:— ‘Though the mills of God grind slowly, yet they grind exceeding small. Though He sit, end wait with patience, with exactness grinds He all.’ The lighter and more soluble particles, during that slow but vast destruction which is going on still to this day, have been carried far out to sea, and deposited as ooze. The heavier and coarser have been left along the shores, as the gravels which fill the old estuaries of the east of England. From these gravels we can judge of the larger animals which dwelt in that old world. About these lost lowlands wandered herds of the woolly mammoth. _Elephas primigenius_, whose bones are common in certain Cambridge gravels, whose teeth are brought up by dredgers, far out in the German Ocean, off certain parts of the Norfolk coast. With them wandered the woolly rhinoceros (_R. tichorhinus_), the hippopotamus, the lion—not (according to some) to be distinguished from the recent lion of Africa—the hyæna, the bear, the horse, the reindeer, and the musk ox; the great Irish elk, whose vast horns are so well known in every museum of northern Europe; and that mighty ox, the _Bos primigenius_, which still lingered on the Continent in Cæsar’s time, as the urus, in magnitude less only than the elephant,—and not to be confounded with the bison, a relation of, if not identical with, the buffalo of North America,—which still lingers, carefully preserved by the Czar, in the forests of Lithuania. The remains of this gigantic ox, be it remembered, are found throughout Britain, and even into the Shetland Isles. Would that any gentleman who may see these pages would take notice of the fact, that we have not (so I am informed) in these islands a single perfect skeleton of _Bos primigenius_; while the Museum of Copenhagen, to its honour, possesses five or six from a much smaller field than is open to us; and be public-spirited enough, the next time he hears of ox-bones, whether in gravel or in peat (as he may in the draining of any northern moss), to preserve them for the museum of his neighbourhood—or send them to Cambridge.