1. MARSUPIATA (Pouched) Kangaroo. 2. MONOTREMATA (Having but one vent) Platypus. 3. RODENTIA (Gnawing) Beaver, Rabbit. 4. EDENTATA (Toothless) Anteater. 5. RUMINANTIA (Chewing) Ox, Deer, Sheep. 6. PACHYDERMATA (Thick skinned) Horse, Elephant. 7. CETACEA (Whale-like) Whale, Porpoise. 8. CARNIVORA (Flesh-eating) Lion, Tiger. 9. INSECTIVORA (Insect-eating) Mole, Hedgehog. 10. CHEIROPTERA (Hand-winged) Bat. 11. QUADRUMANA (Four-handed) Monkey, Ape. 12. BIMANA (Two-handed) Man. These twelve orders of the class "Mammalia," of the division "Vertebrata," (as their names imply), have their peculiarities, such as fit them to their modes of life, as, the medium in which they live, the climate, the food they eat, and the manner of obtaining it. They have all the five special senses, sight, hearing, smell, taste, and touch, but very differently developed in respect to power. Yet, as a whole, they maintain a similitude. They have all internal skeletons, and each part of this skeleton exists in all, but modified to suit different purposes. They have all the peculiar attributes of the "Mammalia," such as suckling their young, being born alive, having four extremities, warm blood, respiration by lungs, and a heart with two auricles and two ventricles. A general description of the anatomy and some of the functions of Man will be given hereafter, and will apply equally to all the Mammalia; always bearing in mind that the difference in structure of every animal, although making it inferior to Man, does not do away with any of the essential qualities, which constitute it one of the members of the highest group; for, although immensely inferior to Man, yet the Mammalia are for the most part greatly superior to all the classes below it, the capability of being educated, being in itself a vast step beyond mere instinct, wonderful though this may be, and developed to an extraordinary degree, as in some of the insects; yet, in these, there is no possibility of improving it, while in some of the Mammalia, as the Dog, Horse, Elephant, and Monkey, there is an evident tendency to progressive improvement when aided by the example and tuition of Man. * * * * * [Illustration: FIG. 59. 1, KANGAROO (Macropas major); 2, OPOSSUM. (Didelphus Virginiana).]