VII 



FLIGHT 253 



held it in position, lets it hang almost vertically down- 

 wards. The wings are held extended, with just a slight 

 bend at the wrist, facing forwards, and so putting the 

 break on as strongly as possible. The tail forms the 

 largest fan it can spread to. For stopping it is perhaps 

 more important than for steering. If the Pigeon be 

 watched from underneath, another very curious point 

 may be made out. It will be seen that the bastard 

 wings are called into play to add to the spread of canvas. 

 They are often spoken of as quite rudimentary, or as 

 useful only in strengthening the wing, though how they 

 can act in this way is difficult to see. One ornithologist 

 imagines that in making a turn a bird extends one 

 bastard wing and revolves round it as on a pivot ! I had 

 long wondered what their use could be or how so many 

 muscles could be wasted on a mere rudiment, when I 

 saw a Pigeon, when checking his speed in order to 

 settle, lift the bastard wing so that daylight was visible 

 between it and the long feathers, this petty appendage 

 jutting out, and impudently spoiling the beautiful line 

 of the front margin of the wing from shoulder to tip. 

 If you stand at the entrance to the British Museum 

 (the Antiquarian Department at Bloomsbury) this 

 curious phenomenon may easily be seen, as the Pigeons 

 which are usually feeding in large numbers on the 

 o-ravel in front fly up and settle overhead on the 

 pediment. In two specimens of Kestrel Hawks which 

 I have examined, the extension of the wing necessarily 

 extended the bastard wing, the tendon within the 

 anterior membrane attaching not only to the metacarp 

 but also to the thumb. The purpose of this is not clear, 

 nor have I noticed anything of the kind in other birds. 



