ii6 



ANIMALS OF LAND AND SEA 



contrary to the habit of most water birds which swim with 

 their feet only, the wings being used but httle if at all. The 



rheas are peculiar in 

 sometimes running 

 with one wing raised 

 like a sail, no one 

 knows why. The 

 ostriches flap both 

 wings in running 

 more or less. In the 

 emus, cassowaries 

 and kiwis the wings 

 are extremely small. 

 The ducks, geese, 

 swans and flamingos 

 for part of the year 

 are flightless, for 

 when they moult all 

 of their wing feathers 

 are lost at the same 

 time, not one by one 

 as in the case of 

 other birds, and they 

 cannot fly until these 

 grow out again. But 

 as these birds are 

 inhabitants of vast 

 marshes, swamps, 

 lakes, isolated reefs 

 and islets, or remote 

 regions where their 

 enemies cannot follow them they do not suffer from the tempo- 

 rary loss of flight. 



The bats vary much less in bodily form and in the shape of 

 their wings than do the birds, and their flight is much more 

 uniform. None of them soar, and none of them gUde. Unlike 



Figs. 251-261. Ant "guests," a Lady-bird, 

 and a Pangonid Fly. 



For explanation of the figures see pp. xviii, xix. 



