INSECT LIFE 163 



delicious blend of moist and dry which in May we 

 talk of as growing weather. Year after year I have 

 noticed that the orange tip butterflies appear on the 

 wing at such a time. 



The orange tip seems a pretty illustration of that 

 flight by the "waved track" I have spoken of. It 

 makes, for its feeble-looking flight equipment limp 

 and thin body and wings without stiffness or cutting 

 power rather quick headway, driving itself forward on 

 to the crest of its wave of motion, and at the end 

 of each stroke, or, rather, at the end of each journey 

 a foot, perhaps, in length which the stroke results 

 in, there appears to be what I suppose might be called 

 a dead point ; the crest of the wave, that is, ends in 

 a point, and then a fresh stroke of the wings (all four 

 wings act together, of course) is delivered, which jerks 

 the little butterfly forward till it reaches the pointed 

 crest of the next wave. 



Jerk is rather a distinct feature of the flight of the 

 orange tip; the strokes do not appear though our 

 slow sight may well be tricked here to glide so 

 smoothly, imperceptibly into each other as we know 

 they do in other forms of flight ; for example, in the 

 figure-of-eight hover of the kestrel or the sphinx 

 moth. But, though the orange tip looks so ill 

 equipped to face aerial difficulties, he must fly many 

 miles on a hot and fairly still May day. He is up 

 and down the sunny field side or the turf by the road 

 scores, probably hundreds, of times between ten in 



