museum, I would yet further ask you to mark the place of the human skeleton in the great gallery. It stands--at least it stood only a few years ago--in the same apartment with the huge mammifers. And it is surely worthy of remark, that while in both the sacred and geologic records a strongly defined line separates between the period of plants and the succeeding periods of reptiles, and again between the period of reptiles and the succeeding period of mammals, no line in either record separates between this period of mammals and the human period. Man came into being as the lastborn of creation, just ere the close of that sixth day--the third and terminal period of organic creation--to which the great mammals belong. Let me yet further remark, that in each of these three great periods we find, with respect to the classes of existences, vegetable or animal, by which they were most prominently characterized, certain well marked culminating points together, if I may so express myself,--twilight periods of morning dawn and evening decline. The plants of the earlier and terminal systems of the Palæozoic division are few and small: it was only during the protracted _eons_ of the Carboniferous period that they received their amazing development, unequalled in any previous or succeeding time.[16] In like manner, in the earlier or Triassic deposits of the Secondary division, the reptilian remains are comparatively inconsiderable; and they are almost equally so in its Cretaceous or later deposits. It was during those middle ages of the division, represented by its Liassic, Oolitic, and Wealden formations, that the class existed in that abundance which rendered it so peculiarly, above every other age, an age of creeping things and great sea monsters. And so also, in the Tertiary, regarded as but an early portion of the human division, there was a period of increase and diminution,--a morning and evening of mammalian life. The mammals of its early Eocene ages were comparatively small in bulk and low in standing; in its concluding ages, too, immediately ere the appearance of man, or just as he had appeared, they exhibited, both in size and number, a reduced and less imposing aspect. It was chiefly in its middle and latter, or Miocene, Pliocene, and Pleistocene ages, that the myriads of its huger giants,--its dinotheria, mastodons, and mammoths,--cumbered the soil. I, of course, restrict my remarks to the three periods of organic life, and have not inquired whether aught analogous to these mornings and evenings of increase and diminution need be sought after in any of the others.