HUMMINGBIRDS 



intellectually speaking, worth many hovering on 

 the wing. We learn, for instance, that all is not 

 pigment that glitters, and that the glorious, ruby- 

 gold gorget makes "a bit of flying rainbow" a 

 scientific truism. A throat feather held up to the 

 light is plain dull gray, but when the sun plays 

 obliquely upon its surface it dazzles the eye. The 

 dull feather is the background of cloud, the surface 

 prism lines are drops of rain; the result in each 

 case — storm or feather — is a rainbow. The tiny 

 wing feathers are too useful to share the luxury 

 of ornamentation; their mission is to beat upon the 

 air, to throb so skilfully, leaning upon it with an 

 exquisitely exact pressure of two grams, that a 

 corresponding weight of flesh, bones and feathers 

 is held aloft and stationary. When at rest the 

 wings are folded away out of sight, when in use 

 they vanish into an intangible blur. 



The way of a hummingbird's wing in the air will 

 end our anatomy, but the marvel of it is like a 

 vista into an unknown country. The exact physi- 

 ology and the mechanical formulse are to be 

 searched for in technical books, but the manner, 

 the superficial why of it is very literally within 

 arm's reach. Try — and fail most dismally — to 

 wave your arms up and down fast enough to be- 

 come a blur. Then attempt — and succeed — in 

 shaking your hands to the vanishing point. Our 

 upper arm, from elbow to shoulder is relatively 

 long, our wrist bones exceedingly short, and on 

 plucking a hummingbird's wing we find the upper 



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