176 THE REIGN OF LAW. 



with such velocity as to elude the eye. The action 

 of the wing in all these cases is far too rapid to 

 enable the observer to detect the exact difference 

 between that kind of motion which keeps the bird 

 at absolute rest in the air, and that which carries it 

 along with such immense velocity. But there can 

 be no doubt that the change is one from a short 

 quick stroke delivered obliquely forward, to a full 

 stroke, more slow, but delivered perpendicularly. 

 This corresponds with the account given by that 

 most accurate ornithological observer, Mr Gould. 

 He, says: "When poised before any object, this 

 action of the wing is so rapidly performed that 

 it is impossible for the eye to follow each stroke, 

 and a hazy semicircle of indistinctness on each 

 side of the bird is all that is perceptible." There 

 is another fact mentioned by those who have 

 watched their movements most closely which 

 corresponds with the explanation already given 

 — viz., the fact that the axis of the Humming 

 Bird's body when hovering is always highly 

 inclined, so much so as to appear almost per- 

 pendicular in the air. In other words the wing- 

 stroke, instead of being delivered perpendicularly 



