The tail of the duck-bill is short, thick, and pointed; it is of very little use in swimming, and for that matter the hind-feet are also little used in the water, the broadly webbed fore-feet being the chief paddles. For almost three quarters of a century the question of the young of the duck-bill paradox was undecided. Report was that the creature laid eggs; but then it was a mammal and fed its little ones with milk: how could any mammal lay eggs? In 1884 the matter was finally settled by indisputable proofs. The duck-bill mother lays two eggs, less than an inch long and cased in strong but flexible shells. When the little ones emerge from the shell they are exceedingly small, and are fed with milk from milk-glands in the skin of the mother, to which they attach themselves. They grow rapidly, and when they are weaned are given insect-food. Shortly after this they are led out of the tunnel, and at once swim with ease. LESSON XXVIII. BESIDE AUSTRALIAN RIVERS. “He can behold Things manifold That have not yet been wholly told-- Have not been wholly sung or said.” --LONGFELLOW. The famous mallangong has a cousin almost as marvellous as itself. Its common name is the porcupine ant-eater; its scientific name is Echidna. When first the habits and anatomy of the duck-bill had been investigated the question arose: Was this a lonely species, having resemblances to many animals and close relationships with none; sole representative of its order; as isolated as the hatteria? A search among the animals of Australia brought to light another relative. [Illustration: “LOW DOWN IN THE SCALE.”] The new animal inhabited the rocky districts and was plentiful in New South Wales. There, among the mountains, it burrowed in loose sand brought down by the water-courses, or hid in crevices of the rock. It wore the quill overcoat of the sea-urchin, and when coiled to sleep looked not unlike a large specimen of that remarkable star-fish.[57] In size the echidna is about like the European hedge-hog (not our porcupine); it wears spurs like a rooster; it has the toothless jaws and the long flexible tongue of the ant-eater. It is entirely insectivorous in its diet, and from that and its quills, like a porcupine, it has its common name, “the porcupine ant-eater.”