CHAPTER VIII.

THE MAMMALIA OR MILK-GIVERS, THE SIMPLEST SUCKLING MOTHER, THE ACTIVE POUCH-BEARERS, AND THE IMPERFECT-TOOTHED ANIMALS 181

PICTURE-HEADING--Scene in the Triassic Period, with small Marsupials _Microlestes_, whose remains are found earlier than the toothed birds. (Restored conjecturally from the nearest living representative, Myrmecobius.) In the water large swimming reptiles.