DRAGON-FLIES 37 



in mid-air. Possibly this accounts for the smallness 

 of the antennae, which if we may judge by their size 

 and structure can be of little service as sense-organs ; 

 for in insects whose food-getting and other activities 

 are known to be largely governed by smell the 

 antennae are usually markedly developed. The mouth- 

 parts of a dragon-fly are of the biting type, the 

 mandibles being exceptionally large and powerful ; 

 but both pairs of maxillae are greatly flattened and 

 otherwise modified, forming, in conjunction with the 

 broad upper lip or labrum, a trap for seizing and 

 holding the prey. Another peculiarity of the dragon- 

 fly is the arrangement of its thoracic segments, more 

 especially the meso- and metathorax. These, when 

 viewed laterally, are seen to slope forward in such a 

 way that while the wings are carried backwards all 

 the six legs are brought close together under the 

 mouth, where they serve as a kind of basket for 

 holding the prey while it is being devoured. If a fly 

 be offered to a captive dragon-fly, it uses its legs to 

 seize the victim, but the capture is probably effected 

 by the mouth-parts when the insect is flying freely in 

 the air. All dragon-flies have four wings, which are 

 glassy in texture, and traversed by a complex network 

 of veins. Each is actuated by powerful muscles, 

 and can be moved separately ; while the very long 

 abdomen supplies unique facilities for steering. It is 

 said that the larger dragon-flies sometimes fly back- 

 wards, but this assertion still calls for verification. 

 Nevertheless, their powers of flight, especially where 

 rapid manoeuvring is concerned, surpass those of any 

 other insect. The general resemblance of a dragon-fly 

 to a man-made aeroplane is not without significance. 

 The female dragon-fly (according to her kind) either 



