AEKIAL LOCOMOTION 257 



AY hen the direction of movement varies, the inclina- 

 tion of the plane of the wing- varies also, and for a 

 moment this plane must become vertically disposed. 

 This may be seen in the first image of the same figure, 

 for in this instance the wing looks exactly the same 

 size, and has the same appearance, as in the case of 

 the motionless insect. 



The balancers can be distinctly seen, and the posi- 

 tion of these organs seems to vary according to that of 

 the wings. Careful observation of a great number of 

 photographs taken under different conditions will no 

 doubt determine the nature of the movements of these 

 structures. 



Finally, we by no means despair of being able to 

 apply chronophotography on fixed plates to the study 

 of insect movement, and of thus being able to obtain 

 a sufficient number of photographs to demonstrate all 

 the phases of the wing movement. 



Some of our attempts have already shown that under 

 certain conditions of illumination, the insect can be 

 photographed as a bright object standing out against 

 a dark background. 



