Vu es FLIGHT 221 
Messrs. Wyles’s photographs of Gulls, flying horizon- 
tally at some height from the sea, there is not a single 
one among the large number that has its wings flexed. 
(See frontispiece.) 
Figures described by different parts of the Wing. 
If you take an insect (a Bluebottle, for instance, or a 
Drone) and hold it down, the wing tips as they vibrate 
Fic. €0 (after Marey). 
Figure described by tip of Crow's wing. 
The backward movement near_/7 is largely due to the flexing, the forward movement 
near s? to the straightening of the wing. 
will be seen to describe a figure of 8. If the sunlight 
be made.to fall upon them, it will be all the clearer.. 
I haye tried painting the tips with body white, but. 
the rapid. vibration soon dislodges the paint. It is 
much harder to discover the trajectory of a bird’s 
wing. Professor Pettigrew has strongly insisted that 
it is an’8 as in the case of insects, but the lower circle 
1 [ have corrected the mistake by which the words “right” 
and “left” have been accidentally transposed in Professor 
Marey’s explanation of the figure. 
