Page:First course in biology (IA firstcourseinbio00bailrich).pdf/434

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The lowest order of mammals contains only two species, the duckbill and the porcupine ant-eater, both living in the Australian region. Do you judge that the duckbill of Tasmania (Fig. 359) lives chiefly in water or on land? Why? Is it probably active or slow in movement? It dabbles in mud and slime for worms and mussels, etc. How is it fitted for doing this? Which feet are markedly webbed? How far does the web extend? The web can be folded back when not in use. It lays two eggs in a nest of grass at the end of a burrow. Trace resemblances and differences between this animal and birds.

Fig. 359.—Duckbill (Ornithorhynchus paradoxus).

Fig. 360.—Spiny Ant-eater (Echidna aculeata). View of under surface to show pouch. (After Haacke.)

The porcupine ant-eater has numerous quill-like spines (Fig. 360) interspersed with its hairs. (Use?) Describe its claws. It has a long prehensile tongue. It rolls into a ball when attacked. Compare its jaws with a bird's bill. It lays one egg, which is carried