THE PLAY OF ANIMALS. 259 



says that early and late in the day it mounts up ver- 

 tically to a moderate height, then flies off to a distance 

 of twenty yards, describing a perfect curve in its pas- 

 sage; turning, it flies back over the imaginary line it 

 has traced, and so on, repeatedly, appearing like a pen- 

 dulum swung in space by an invisible thread." * Audu- 

 bon thus vividly portrays the American night hawk: 

 " Their manner of flying is a good deal modified at 

 the love season. The male employs the most wonderful 

 evolutions to give expression to his feelings, conduct- 

 ing them with the greatest rapidity and agility in sight 

 of his chosen mate, or to put to rout a rival. He often 

 rises to a height of a hundred metres and more, and 

 his cries become louder and more frequent as he mounts, 

 then he plunges downward with a slanting direction, 

 with wings half open, and so rapidly that it seems in- 

 evitable that he should be dashed in pieces on the 

 ground. But at the right moment, sometimes when 

 only a few inches from it, he spreads his wings and tail 

 and turning soars upward once more.^' The same au- 

 thority describes the mocking bird as fluttering about 

 his mate and regularly dancing through the air. The 

 whitethroat leaves his perch in a tree top while singing, 

 rises ten to twenty yards and lets himself fall, still sing- 

 ing, either fluttering in a slanting direction or, with 

 folded wings, almost perpendicularly. 



The reed bird, while his mate is sitting on the nest, 

 flies up in the air diagonally and floats with his wings 

 held so that they nearly touch over him. The wood lark 

 mounts in the same way, constantly singing, and after 

 describing one or more circles falls or plunges down 

 and slowly returns to the tree from which he set out. 



* The Xaturalist in La Plata, p. 2G3. 



