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ON THE POSITIONS ASSUMED BY BIRDS 

 IN FLIGHT. 



BY 

 BENTLEY BEETHAM, f.z.s. 



II. STEERING, SLOWING-UP, AND TURNING. 



The old idea that the wings of a bird simply flap up and 

 down, and that by some means the body travels steadily 

 along on a level horizontal course, has long been dispensed 

 with. It is, however, difficult to reahze, but none the 



FIGURE 1. — THE TWO EXTREMES OF POSITION. 

 {Photographed by Bentley Beetham.) 



less true, that at each full wing-beat the body is raised 

 as well as propelled. Perhaps this can be more readily 

 appreciated by reference to a photograph, such as that 

 represented in Figure 1. 3y good fortune the two Gannets 

 shown there so near together exhibit the two extremes 

 of the positions which these birds ordinarily assume in 

 flight. In the top left-hand bird the wings are raised 

 and the body seems to be dependent from them, while 

 in the lower bird the wings are far depressed a^nd the body 



