144 THE ZOOLOGIST. 



wake occurs also in the Herring-Gull. In the presence of Mr. 

 Evans I was able to observe Herring- Gulls flying without visible 

 legs, or with only a ruffle on the feathers to indicate where the 

 legs were hidden. Lastly, Mr. Evans was so fortunate as to 

 observe a bird actually tuck up its leg while he looked at it. 



Nothing could be more striking in illustration of the great 

 and constant assistance which the legs of birds afford to their 

 wings in flight. It is almost as if, to some birds, the legs are 

 nearly more important as organs of flight than of progression 

 on land. 



No more interesting birds exist than the Kites for the pur- 

 pose of observations of the present kind. Where food is abun- 

 dant, as in Cairo or Bombay, or in many harbours, as those of 

 Japan, their graceful evolutions may be watched for hours. Kites 

 have considerable power of movement of their legs while on the 

 wing. They can pick up, carry, and even eat their food while in 

 the air. On the other hand, the legs are not long enough to 

 oust the long forked tail in its varied functions, since they reach 

 only to about the base of the rectrices when pointing backward. 

 After watching Kites on numerous occasions I at length came to 

 the conclusion that the posterior position of the legs is for them 

 the normal one. I thus agree with other writers ; but I was 

 so long in coming to this decision, and I made so many contra- 

 dictory observations, that I feel sure that Kites, like Gulls, can 

 use either the backward or the forward position. 



The tail of a flying Kite is constantly undergoing slight 

 modifications or alterations of position. Besides changes in the 

 amount of expansion, it is constantly changing its plane, now in 

 one direction and now in another, evidently with a rudder-like 

 effect or action. The need of a rudder of some kind seems to 

 find its satisfaction in length of tail* or of leg, but it is curious 

 that so many of the most powerful and persistent fliers should 

 possess very short legs, which must be quite useless for purposes 

 of flight. In these, however, I think, it will be found that there 



* In mammals a long tail may be used as a rudder. The late Sir Samuel 

 Baker remarks that the Cheetah (Felis jubata) is assisted by its tail when 

 turning sharply at full speed, although he does not state exactly how (cf. 

 'Wild Beasts and their Ways,' p. 168), and I have personally observed a 

 similar function in the (in life) beautiful tail of the South African Ground 

 Squirrel (Xerus capensis). 



