FIG. 60.—PLATYPUS, OR DUCK-BILL (Ornithorynchus).
2. The Monotremata includes the Duck-bill, called also "Platypus," and "Ornithorynchus paradoxus," (fig. 60), a most singular combination of the forms of the mammal and the bird. It has a mouth resembling the bill of a Duck, and several other peculiarities, which lead to the consideration of it as one of the connecting links between the forms of the Mammalia and Birds.
FIG. 61.—BEAVERS (Castor fiber).
3. The Rodentia comprise the Rat, Beaver, Rabbit, Hare, Mouse, &c. They live upon almost any kind of vegetable matter; the Rat and Mouse will eat anything they can get. Their incisor teeth are two in front of each jaw, and are chisel-shaped and very sharp; they are so constructed that they shall be kept sharp by being used, which is effected by the hardest part or enamel being in front in a thin layer, so that it is not so easily worn away as the bony part. If these animals be fed on soft food, their teeth continue to grow nevertheless, and protrude from their mouths in a most singular way. The Beaver (fig. 61) is almost aquatic in its habits, it gnaws through the stems of trees, and uses them to dam up the water of the stream they inhabit, so as to secure a constant supply. They build houses or huts of wood, mud, and stones, which they unite in constructing. These houses have their entrances beneath the water, so that the Beavers dive to enter them; they have two divisions or rooms in them, and are sufficiently large to lodge several families. The Rat is too well-known to need much description. The brown or Norway Rat has only been an inhabitant of this country about forty years, the black Rat being before that time the usual house Rat, but it is now almost exterminated, specimens being very rare. There are several other species of Rats; the best known is the Water Rat, who burrows in brooks and ditches, and partly lives in the water. Of the Mouse there are also several species. Besides the usual house Mouse, there is the wood Mouse, which forms a magazine of grain and nuts underground for winter store; and the harvest Mouse, which builds a little round nest between the stalks of corn. The Squirrel is also of this order. This pretty little creature lives in the trees, chiefly feeding upon nuts; can leap well, and run up the branches of trees with surprising agility. The Flying Squirrel has a broad expansion of skin between the fore and hind legs on each side, so that when stretched out, they form a sort of parachute; this enables the creature to leap to a great distance from tree to tree, and supports it in the air as it goes. The Porcupine (Hystrix cristata), so celebrated for its quills, which supply a sort of defensive armour, is of this order.
FIG. 62. ANTEATER (Myrmecophaga jubata).
4. The Edentata, or Anteaters, have no teeth, but a peculiarly shaped tongue, which is covered with viscid mucus, and which they project and retract with great rapidity, causing the Ants and Termites, on which they feed, to adhere to it, and be carried into their mouths. The Great Anteater (Myrmecophaga jubata, fig. 62) is a very extraordinary animal in appearance; it has an enormously prolonged nose, and the back is covered with a sort of mane; the tail, also, is of prodigious size, and very bushy; when this curious animal lies down to sleep, the long snout is thrust under it, and the tail laid across the back, the end of the snout projecting behind. In this position, it would lead anyone to suppose that the head was where the tail really is, and that when looking at the creature's hinder part, they were looking at its head; and the sudden reversal of the position of these parts, when it gets up quickly, is certainly extremely ridiculous.
FIG. 63.—GROUP OF RUMINANTS.
1, Ox (Bos taurus); 2, Sheep (Ovis aries); 3, Red Deer (Cervus elaphus); 4, Camel (Camelus Arabicus); 5, Llama (Pacos).