He fastened a small piece of paper to the tip of a crow's wing, 

 and as the bird flew in front of a perfectly black screen he 

 took a photograph of this moving speck of white, while, of 

 course, no image of the crow appeared on the plate. The 

 resultant picture gave a series of " figure of 8 loops " as one 

 would make this figure with a pen, contriving to make the 

 lower loop very smaU, and the upper loop very large. But as 

 the wing-beat increased in speed the lower loop gradually 

 faded out. 



These movements of the wing, however, are descriptive 

 rather of what takes place during very vigorous flight, as 

 when the bird is getting up " steam." When he is weU 

 under way there is no need for these long and very tiring 

 strokes, except in the case of birds like= the pheasant or the 

 duck. A gull, when in full career, does not, apparently, raise 

 the wings very high, nor depresses them very low, nor does 

 it flex the wings at the wrist-joints. 



Stopping and turning movements are generally extremely 

 difficult to follow, because they are performed so quickly. 

 They can be seen fairly easily in the case of some of the larger 

 birds. Ducks, as is well shown in one of our coloured Plates, 

 draw the head backwards, tilt the body upward, thrust the 

 feet forward, and spread the tail, at the same time turning 

 it forwards. Gulls and pigeons too may be watched with 

 profit. 



38 



