442 NORTH AMERICAN BIRDS. 



their flight, are so insect-like. They pass from bush to bush as if suspended 

 in the air, and pause over each flower, vibrating their wings, in precisely the 

 same manner with the Sphinxes, and with the same humming sounds. 



The flight of the Humming-Bird is of two kinds. One of these is used 

 for a horizontal movement, and is so rapid that one can hardly follow it 

 with the eye. This is accompanied by a kind of hissing sound. The other 

 seems to keep the body in the air immovable, in one spot. For the latter 

 purpose the bird assumes a position nearly vertical, and beats its wings with 

 great intensity. These organs must vibrate all the more rapidly, because 

 the immobility of the body requires a shorter stroke, and therefore the more 

 frequently repeated. The equilibrium of the body is preserved by the alter- 

 nate up and down strokes of the wings, no inconsiderable force being re- 

 quired to keep its immobility, besides that requisite for neutralizing the 

 weight of the body. 



The Humming-Bird is entirely aerial. They pass with the rapidity of an 

 arrow, stop, rest for a few seconds on some small branch, and then sud- 

 denly depart with so much rapidity that we cannot trace its flight. They 

 disappear as if by enchantment. Their life is one of feverish excitement. 

 They seem to live more intensely than any other being on our globe. From 

 morning to night they traverse the air in quest of honeyed flowers. They 

 come like a flash of light, assume a vertical position without any support, 

 throw their tail forward, expanding it like a fan, vibrating their wings with 

 such rapidity that they become absolutely invisible, plunging, at the same 

 time, their thread-like tongues to the bottom of some long corolla, and then 

 they have gone as suddenly as they came. They are never known to rest 

 on a branch in order more at their leisure to plunge their tongue into the 

 flower. Their life is too short for this delay ; they are in too great haste ; 

 they can only stop long enough to beat their wings before each flower for a 

 few seconds, but long enough to reach its bottom and to devour its inhabi- 

 tants. When we take into consideration how entirely aerial is their life, and 

 the prodigious relative force requisite to enable them to keep suspended in 

 the air during the entire day, almost incessantly, either in rapid motion or 

 accomplishing the most violent vibrations, we can but be amazed at the 

 extraordinary powers of flight and endurance they manifest. 



The Humming-Bird enjoys even the most tropical heat, avoids shade, 

 and is easily overcome by cold. Though some travellers speak of having 

 met with these birds in the depths of forests, Saussure discredits their 

 statements, having never found any in sucli situations. They prefer open 

 flowery fields, meadows, gardens, and shrubbery, delighting to glitter in 

 the sun's rays, and to mingle with the swarm of resplendent insects with 

 which tropical regions abound, and with the habits of wliich their own so 

 well accord. Nearly all live in the open sun, only a very few are more or 

 less crepuscular and never to be seen except very early in the morning or in 

 the evening twilight. 



